Preheat the oven to 265°F / 130°C (110° fan-assisted).
Add the egg whites, cream of tartar, and a pinch of salt to the bowl of a stand mixer with a whisk attachment fitted. Whip on low speed for 1-2 minutes until the egg whites become foamy and opaque.
Gradually increase the speed to medium-high, then start adding the sugar, one tablespoon at a time. Let the mixture whip for 15-30 seconds in between each spoonful to allow the sugar to dissolve.
Once all the sugar has been added, whip for another 30 seconds, then check to make sure there are no sugar granules that haven't dissolved. You can do this by rubbing a little bit of meringue between your fingers, it should feel completely smooth. If it is gritty at all, keep whipping.
Scrape down the sides of the bowl and then add the vanilla. Turn the mixer up to high speed and whip until glossy, stiff peaks form. This means that the meringue peaks should stand up tall and straight without drooping.
Sift in the cornstarch and fold it gently into the meringue.
Draw an 8 or 9-inch circle onto some parchment paper, then flip it over and put it on. your baking sheet. use a little blob of meringue in each of the four corners to stick the parchment paper to the pan. Spoon the meringue out into the circle.
Use a spatula or spoon to shape the meringue into a round shape. Make a slight dip in the middle for holding your toppings. Run your spatula up the sides of the meringue to make indented lines that slope into the middle as they go up - this will make the pavlova more stable and stops the toppings from sliding off.
Gently place the pavlova into the preheated oven and bake for 10 minutes. Then, without opening the oven door, turn the temperature down to 210°F / 100°C (80° fan-assisted) and bake for 1 hour and 30 minutes. The bake time may vary, but you'll know the pavlova is ready when the outside is dry to the touch and it lifts away from the parchment paper easily. Do not open the oven door to check this until at least 1 hour 15 minutes of baking.
Once it's ready, turn the oven off and let the pavlova cool in the oven for at least an hour, but preferably until it has cooled completely to room temperature. This will prevent cracking.
Assemble and Decorate the Pavlova
Put the heavy cream, sugar, and vanilla into a bowl and whip until soft to medium peaks form.
Spoon the cream on top of the cooled pavlova, then top with fresh berries.
Notes
Ingredients Notes:
Egg Whites - It's much better to use fresh eggs and separate them, rather than using boxed egg whites. Carton egg whites often won't whip up well, which can make your meringue flop. Be extremely careful when separating your eggs, as even the tiniest trace of egg yolk in the whites will stop them from whipping up properly. Tip: The egg whites will whip up better at room temperature, but they are easier to separate while cold.
Sugar - Superfine sugar (caster sugar) is best as it will dissolve into the egg whites easily. Regular granulated sugar may not dissolve and will leave you with grainy meringue. You can make your own superfine sugar by pulsing regular sugar in a food processor.
Cream of Tartar -. If you can't find cream of tartar, you can use 1 teaspoon lemon juice instead.