These S'mores Brownies are next level. The gooiest, decadent chocolate brownies with a graham cracker crumb base and a thick layer of toasted homemade marshmallow frosting.

It doesn't get much more indulgent than ooey gooey s'mores in brownie form. These decadent s'mores brownies have it all - the graham cracker base, the melty, fudgy brownies and the sweet marshmallow layer which has been torched to create that delicious toasted marshmallow flavor of s'mores.
I've been having fun experimenting with developing fun brownie recipes lately, like my Red Velvet Brownies and my Tiramisu Brownies. But one of my most popular recipe mash-ups are my S'mores Cupcakes, so I wanted to try to make a S'mores brownie recipe and suffice it to say they were a resounding success! If you're a s'mores lover you're going to want to save this one!
Jump to:
- Why You'll Love This Recipe
- Ingredients
- Make the Graham Cracker Crust
- Make the Brownies
- Make the Marshmallow Frosting
- How to Decorate S'mores Brownies
- Video
- Making an Interactive Dessert
- Can You Use Box Mix to Make S'mores Brownies?
- Shortcuts
- Common Mistakes
- Substitutions
- Variations
- Equipment
- Storage
- More Decadent Brownie Recipes
- Recipe
Why You'll Love This Recipe
- These S'mores brownies are over-the-top decadent - if you're looking for a dessert with the 'wow' factor, you've found it!
- Enjoy the taste of camping trip s'mores without the need for a campfire - perfect for parties and dinners.
- Torching the marshmallow is fun, you could make it a part of the experience that people get to torch their own s'mores brownie!
Ingredients
Though there are multiple different elements to this S'mores Brownie recipe, the ingredients list is actually fairly simple as a lot of the ingredients double up for different elements.
- Graham Crackers - Or digestive biscuits if you can't find graham crackers.
- Butter - Use unsalted butter - it doesn't need to be brought to room temperature as we will be melting it.
- Eggs - The whole eggs are for the brownie batter, use large eggs and always free-range if you can.
- Egg Whites - For best results, use fresh eggs, separated, rather than carton egg whites. You can technically use carton egg whites but the meringue may not whip up as much so your marshmallow will be less fluffy and voluminous. Don't throw away the egg yolks, you can use them in another recipe, like my Custard Donuts).
- Dark Chocolate - You definitely want to use dark chocolate here. Even if you're not a dark chocolate fan, it will give the brownies a deep chocolate flavor and there will still be plenty of sweetness from the other ingredients.
These brownies don't contain any cocoa powder, the chocolate flavor all comes from the chocolate, so make sure it's high-quality. Also use real chocolate bars with at least 70% cocoa solids - not chocolate chips or candy bars. - Sugar - Use superfine white sugar (caster sugar) as it will dissolve into the egg whites easily. If you can't find this, regular granulated sugar is fine too.
- Vanilla - Use vanilla extract or vanilla bean paste. Bean paste will make some pretty speckles in your marshmallow.
- Cream of Tartar - This will help keep the marshmallow frosting thick and stable. If you can't find it, you can use lemon juice instead (twice as much lemon juice as cream of tartar), but your frosting may not be as stable without it.
See the recipe card for quantities.
Make the Graham Cracker Crust
- Preheat Your Oven to 350°F / 180°C (160° fan-assisted) and line a 9-inch square pan with parchment paper.
- Put the graham cracker pieces or digestive biscuits in a food processor and blitz them until you have fine graham cracker crumbs. If you don't have a food processor you can put them in a Ziploc bag instead and bash them up with a rolling pin.
- Melt the butter in the microwave in 30-second increments and then pour it into the crumbs. You can pour the melted butter straight into the food processor, or mix into a bowl if you are using the bag method. Mix until everything is well combined and it looks like wet sand.
- Tip the crumb mixture into the prepared pan and use your hands or a glass to flatten it out into a tightly packed, even layer. Make sure you get into all the corners. Set aside.
Make the Brownies
This is my ultimate fudgy brownie recipe and it's absolutely perfect for this s'mores brownies recipe because they are the most gooey and chocolatey brownies - just like the melty chocolate of s'mores.
- Chop up your chocolate up on a cutting board into small chunks. Add the chocolate chunks to a microwave-safe bowl along with the butter and melt in 30-second increments, stirring in between, until the chocolate and butter have both melted. Set aside
- In a large bowl, whisk together the eggs and sugar until thick and pale - kind of like custard. There is no need for an electric mixer here, 30 seconds of vigorous whisking by hand should do it.
- Pour the melted chocolate mixture into the egg/sugar mixture, add the vanilla and mix together gently with the whisk until combined.
- Sift in the dry ingredients, including the flour and the salt, use a spoon or spatula to fold the flour in to the brownie batter until there are no more visible lumps of flour. It's okay if the batter has some lumps, as long as you can't see any white flour.
- Pour the brownie batter into the baking pan, on top of the graham cracker layer and let it spread out evenly.
- Bake for 25-30 minutes for soft, gooey brownies, or 30-35 minutes for more solid, dense brownies. Personally, I think letting the brownies be slightly underbaked here makes them even more like s'mores.
When they are done, the top of the brownies will be dry and shiny, and when you test the middle of the brownies with a skewer, it will come out slightly chocolatey. If it is caked in a thick layer of raw batter, the brownies need longer. Baking time can vary depending on your oven, so look out for the physical signs they are ready.
- Let the brownies cool in the pan completely before attempting to remove them. If you take them out too soon they will turn into a big sloppy mess all over your counter. If they still seem too soft when trying to take them out, put them in the fridge for 20 minutes to firm up before taking them out of the pan.
Make the Marshmallow Frosting
They wouldn't be s'mores brownies without marshmallow, so let's get to the fun part! The marshmallow layer is effectively a swiss meringue. It might seem daunting but it's actually very easy to make.
- Make a double boiler by placing a heatproof bowl over a small saucepan with a few inches of water in it. Do not let the bottom of the bowl touch the hot water. Turn the heat on medium-low so the water is simmering.
- In the bowl, whisk together the egg whites, sugar and cream of tartar. Keep whisking constantly until the mixture is warm and the sugar has dissolved. You don't have to whisk vigorously, just enough to keep it moving. You can test if it's ready by rubbing some of the mixture between your fingers - if you can feel any grains of sugar it needs longer.
If you would like to use a thermometer, you want the egg whites to reach a temperature of 160°F / 71°C.
- Once the egg whites are warm and the sugar has dissolved, whip the mixture on high speed, either with a stand mixer or an electric whisk. (I just use the metal bowl from my stand mixer for the double boiler, then move it right over to the mixer without needing to transfer it to another bowl).
- Whip on high speed until stiff, glossy peaks form. Add the vanilla and whip for another 30 seconds - you should be able to make tall shapes with it when it is ready.
Tip: I always recommend weighing your ingredients with a kitchen scale, rather than using measuring cups. It's very difficult to measure accurately with cups and this can mess up your bakes.
How to Decorate S'mores Brownies
There are two methods to decorate your homemade s'mores brownies:
Spread and Slice
- Spread the marshmallow frosting all over the brownie layer and use a spoon or spatula to make lots of shapes and texture on top - this will look super pretty when you toast it.
- Use a kitchen torch to toast the marshmallow all over until it is golden brown. I like mine quite dark and toasty as I am one of those freaks that likes to cremate my s'mores... but you can do yours however you like.
- Once toasted, use a sharp knife to cut your s'mores brownies into 9 or 16 squares. These are quite rich and intense so I recommend the 16 squares.
Slice and Pipe
Alternatively, you can slice your brownies first. This is good if you want to pipe your marshmallow frosting on top for a more elegant finish.
- Slice the brownies just as you would any regular brownies, into 9 or 16 slices.
- Place the marshmallow frosting in a piping bag with your chosen decorating tip and pipe however you please.
- Torch with the blow torch until golden brown.
Tip
Wipe your knife off with some paper towels in between each slice to get nice clean cuts.
Video
Making an Interactive Dessert
S'mores brownies are super fun to have as an activity for your guests to interact with. You could slice the brownies once they have cooled and provide each guest with their own brownie and a big bowl of marshmallow frosting in the middle to decorate their own s'mores brownie with.
You could also have optional toppings like candies, melted chocolate and crushed-up graham crackers. If your guests are adults you can even let them torch their own marshmallow with the blowtorch, which is an interactive and memorable experience. I DO NOT recommend this step for kids though as the blowtorch can be very dangerous if not handled properly.
Can You Use Box Mix to Make S'mores Brownies?
I mean... you can, but homemade brownies are going to taste so much better - especially this smores brownie recipe because I have tested it to make the most perfectly gooey, fudgy brownies that taste just like real s'mores.
Brownie mix will never give you the texture or flavor that you will get with homemade, plus this brownie recipe is so quick and easy that you won't really be saving any time by using boxed mix. So yes you could use it, but I encourage you to try the homemade version!
Shortcuts
While the brownies are one area I encourage you not to take shortcuts on, there are other areas where you can cut down the preparation time to make these easy s'mores brownies even simpler.
- Not making the marshmallow from scratch - If making homemade marshmallow frosting sounds like too much of a faff, you can still make these s'mroes brownies without! You can sprinkle the tops of the brownies with mini marshmallows in a single layer about 5 minute before the end of the brownie bake time and let them melt over the top into a layer of gooey toasted marshmallows.
OR you can spread marshmallow fluff over the top of the brownies in place of the marshmallow frosting and torch that just the same.
- Skip the Graham Cracker Layer - If you don't want to make the graham cracker crumb, you can crumble some pieces of graham crackers on top of the brownies instead, or just skip them altogether.
Common Mistakes
Here are some common mistakes people make when baking this s'mores brownies recipe.
- Overbaking the brownies - don't let the brownies bake for too long or they will come out dry and dense. A skewer should still come out slightly moist and chocolatey when they are done.
- Trying to slice the brownies too soon - the s'mores brownies need to be completely cooled before you frost them or slice them, otherwise they will just make a big gooey mess.
- Getting egg yolk into the egg whites - If there is any trace of egg yolk, or any other fat in your egg whites, they will not whip up properly. Be very careful when separating your eggs.
- Adding too much flour - these are nice fudgy brownies to make the s'mores effect - if you add too much flour they will be cakey instead. Not measuring accurately can cause this, which is why I the best way to measure is with a kitchen scale rather than a measuring cup.
Substitutions
- Graham Crackers - If you can't find Graham Crackers you can use Digestive Biscuits or Nilla Wafers.
- Egg Whites - If you don't want to use up whole eggs, you can use cartoned egg whites instead - just know the marshmallow may not whip up as well or be as thick.
- Cream of Tartar - If you can't find cream of tartar, you can substitute with lemon juice - double the amount of lemon juice as cream of tartar. Just know the marshmallow may not be as stable and might not last as long.
Variations
Easier Marshmallow - I have a few suggestions in the 'shortcuts' section above for how you could make this with alternatives to the homemade marshmallow frosting. I do think the frosting is easier to make than it might seem, but there are definitely other options there that will still give you nice gooey marshmallows without making your own.
Mixins - You can add whatever mixins you like into the brownies - chocolate chips, nuts (like my Pistachio Brownies), candies or even more mini marshmallows!
Toppings - For an extra layer of deliciousness, drizzle some melted chocolate and some graham cracker crumbs on top of the marshmallow, just like my S'mores Cupcakes.
Equipment
- 9-inch square pan
- Mixing bowl
- Whisk
- Stand mixer - with whisk attachment. This is for making the frosting.
- Saucepan
- Heatproof Bowl
- Kitchen Torch
Storage
Store your S'mores brownies in an airtight container at room temperature for up to 3 days. Refrigerating the marshmallow frosting may make it become weepy.
These are best when eaten on the same day as the marshmallow can lose some of its stability and fluffiness, depending on the humidity where you are.
To make them last longer you can make the brownies ahead of time and make the marshmallow frosting on the day of serving. The brownies alone will be good for up to 4 days.
More Decadent Brownie Recipes
For more gourmet brownie inspiration, try some of these:
Recipe
S'mores Brownies
Equipment
- Kitchen Torch
Ingredients
For the Crumb Base
- 7 oz Graham Cracker Crumbs 190g / 11 graham crackers or 13 digestive biscuits
- 1 stick Butter 113g
For the Chocolate Brownies
- 1 ½ sticks Butter 170g
- 10.5 oz Dark Chocolate 300g
- 3 Large Eggs
- 1 ¼ cups White Sugar 250g
- 1 cup All-purpose Flour 120g
- ½ teaspoon Salt
- 1 teaspoon Vanilla
For the Marshmallow Frosting
- 4 Large Egg Whites
- 1 cup White Sugar 200g
- 1 teaspoon Vanilla
- ½ teaspoon Cream of Tartar
Instructions
Make the Crumb Base
- Preheat your oven to 350°F / 180°C (160° fan-assisted) and line a 9-inch square pan with parchment paper.
- Blitz the graham crackers or digestive biscuits in a food processor until they are crumbs. If you don't have a food processor you can just put them in a Ziploc bag and bash them to crumbs with a rolling pin.7 oz Graham Cracker Crumbs
- Melt the butter in the microwave in 30-second increments until melted, pour into the graham cracker crumbs and mix together until well combined - it will look like wet sand. (If you're using a food processor you can just pour the butter straight in and pulse until combined).1 stick Butter
- Tip the crumb mixture out into the prepared pan and use your hands or a glass to press the crumbs down into a tightly packed, even layer.
Make the Brownies
- Chop the chocolate into small pieces and put into a heatproof bowl along with the butter. Melt in the microwave in 30-second increments, stirring in between, until totally melted. Set aside.10.5 oz Dark Chocolate, 1 ½ sticks Butter
- In a large bowl, combine the sugar and eggs and whisk until thick and custard-like. This should take about 30 seconds of vigorous whisking by hand. You can use an electric mixer if you prefer but it's not necessary.3 Large Eggs, 1 ¼ cups White Sugar
- Pour the melted chocolate mixture into the egg/sugar mixture, add the vanilla and gently whisk everything together until fully incorporated.1 teaspoon Vanilla
- Sift the sugar and salt into the bowl and use a spoon or spatula to fold everything together until there are no more visible lumps of flour.1 cup All-purpose Flour, ½ teaspoon Salt
- Pour the brownie batter into the cake pan, on top of the crumb base.
- Bake for 25 - 30 minutes for a soft, gooey brownie, or 30 - 35 minutes for a dense, sturdy brownie. Personally, I think having the brownies slightly underbaked really adds to the 'smore's' flavor, but this is down to personal preference. Either way, the top should be dry to the touch and a skewer inserted in the middle should come out either clean or with a little bit of chocolate on it - if it comes out with a big clump of raw batter then the brownies need longer.
- Let the brownies cool in the pan completely before attempting to unmold them, or they will just fall apart into a gooey mess. If they seem too soft to remove easily, try placing them in the fridge for 20 minutes before taking out.
Make the Marshmallow Frosting
- Make a double boiler by placing a heatproof bowl over a small saucepan with a small amount of water in it. Don't let the water touch the base of your bowl. Place the egg whites, sugar and cream of tartar in the bowl and put the saucepan on medium-low heat to bring the water to a simmer.4 Large Egg Whites, 1 cup White Sugar, ½ teaspoon Cream of Tartar
- As the water warms up, whisk constantly to bring everything together. You don't have to whisk vigorously, just enough to keep everything moving. Keep going until the sugar has dissolved - you can test this by rubbing a little piece of the mixture between your fingers to feel for any grains of sugar.If you are using a thermometer, the temperature of the egg whites should reach 160°F / 71°C.
- Once the eggs are warmed and the sugar has dissolved, remove the bowl from the heat, add the vanilla and start whipping on high-speed with a stand mixer or electric whisk. (I just use the metal bowl from my stand mixer for the double boiler, then move it right over to the mixer without needing to transfer it to another bowl).1 teaspoon Vanilla
- Whip the meringue until it is thick and glossy. You should be able to make tall, stiff peaks with it when it is ready.
Assemble the S'mores Brownies
- Once the brownies have completely cooled, unmold them from the pan.
- Slather the marshmallow frosting all over the top of the brownies and spread it out to the edges, making some nice texture on top (that will be pretty when we torch it!). Alternatively, you can slice the brownies first and then pipe the marshmallow frosting onto each individual brownie.
- Using a kitchen torch, carefully toast the marshmallow frosting to your desired toastiness. I like mine very brown and crisp as I think it really adds to the flavor - but you can just do slightly toasted if you prefer.
- Slice the brownies into 9 or 16 squares with a large, sharp knife and enjoy!
Notes
It really helps and I love hearing all your feedback!
Katherine Taylor
Just wanted to let you know that you have “add vanilla” in two different steps. I’m sure either would work, but you may want to check it.
Jules Grasekamp
Thanks Katherine, I have updated that step now!
Jules
Kashmir
So I'm not sure what the issue is, I followed the recipe exactly but they're still in the oven because almost twenty minutes after the original 30 minute bake time they are STILL goopy in the middle. The taste of the batter I've had is excellent so I'm giving a good rating for that but I'm talking a star off just for the excessive bake time that's way longer than the recipe calls for.
Jules Grasekamp
Hi Kashmir,
Thanks for your comment, I'm sorry to hear this about your brownies - how did they turn out in the end?
Because they are super gooey brownies, they will not set completely in the oven like a cake would - they should still be very moist when they are done, and a skewer inserted should still come out slightly chocolatey.
What kind of baking pan were you using? There are lots of things that can affect baking time, including the bakeware, temperature of ingredients, and whether the oven needs to be calibrated or not (this happens so often you wouldn't believe!). That's why I always teach people to look for the signs that their baked goods are done, rather than relying on recipe bake times. It sounds like you were doing this perfectly 🙂
I hope they turned out great in the end!
Jules
Dana L johnson
Good morning, I want to try this but what can I substitute for cream of tartar?
Jules Grasekamp
Hi Dana,
If you can't find cream of tartar, you can substitute with lemon juice - double the amount of lemon juice as cream of tartar. Just know the marshmallow may not be as stable and might not last as long.
If you need to know any substitutions I have a 'substitutions' section in the post that I hope you will find helpful 🙂
Hope you love the s'mroes brownies!
Happy baking,
Jules
Chris Radwanski
As a Canadian I’ve had my fair share of s’mores around the fire, and I was sceptical that this would be anywhere near as good. I was pleasantly surprised with this one, it’s (dare I say it) better than campfire s’mores! The marshmallow topping isn’t as sticky and it’s not sickly sweet.