• Preheat oven to 350°F and line a muffin pan with cupcake liners

Make the Chocolate Cupcakes

• Sieve all the dry ingredients into a large mixing bowl
• Add the eggs, oil, milk and vanilla and beat for a couple of minutes until combined.
• Mix the instant coffee in the hot water and add to the batter, mixing until combined. The batter will be fairly liquid.
• Optional: If you want to, you can add some crumbled up graham crackers to the bottom of each cupcake liner before adding the batter, for extra crunch.
• Spoon the batter into the cupcake liners and bake for 18 -22 minutes or until a skewer comes out clean.

Make the Melty Chocolate Filling

• Chop your chocolate into small pieces and place it in a bowl.
• Heat the cream in a small saucepan until it is scalding hot (little bubbles appear on the surface, this is the stage before it starts to boil).
• Remove from the heat and pour the cream into the chopped chocolate, let sit for 30 seconds.
• Stir the mixture together until smooth and silky. Let cool.

Make the Marshmallow Frosting

• Make a double boiler by putting 1 inch of water in a saucepan and placing a heatproof bowl on top, ensuring the bottom of the bowl doesn't touch the water.
• Put the egg whites, cream of tartar, and sugar into the bowl and whisk constantly - it doesn't have to be vigorous whisking, just enough to keep it moving. Heat until the egg whites are warm and the sugar has dissolved. Check if it's ready by feeling the mixture between your fingers, if it's grainy at all, it needs longer.

  If you want to use a thermometer, the temperature to aim for is 160°F / 71°C.
• Transfer to a stand mixer with a whisk attachment fitted and whip until stiff peaks form.
• Add the vanilla and whip for another few seconds, it should be thick and glossy.

Construct your S'mores Cupcakes

• Once the cupcakes have completely cooled, core out the middle of the cupcake using a cupcake corer or a teaspoon.
• Fill the cavity with chocolate ganache filling.
• Pipe or spread the marshmallow frosting onto the cupcakes.
• Use a kitchen torch to toast the marshmallow.
• Drizzle remaining chocolate filling over the top of the marshmallow frosting and sprinkle with some graham cracker crumbs.