Instructions

To Make the Chocolate Pavlova

1. Preheat the oven to 180°C/350°F (without fan).
2. Using a standmixer or electric beaters, whisk the egg whites in a large, clean bowl until they have tripled in volume and soft peaks form.
3. Turn the speed down to low and slowly add the caster sugar, one spoon at a time until the sugar is well incorporated. As you add the sugar, the mixture will start to become thick and glossy, and stiff peaks will form when you lift the beaters.
4. Remember to scrape down the sides of the bowl.
5. Rub a bit of the mixture between your fingertips to test if the sugar has been fully dissolved; if you don’t feel any grains of sugar, move onto the next step.
6. Add the cornflour, white wine vinegar, vanilla extract and cocoa powder. I do this on low speed with the stand mixer for only 2 to 3 rotations (about 1 second).
7. Fold through the chopped chocolate.
8. Line a baking tray with baking paper and spoon the pavlova mixture onto the tray into a round shape. I like to dollop the mixture on top of each other into a high pile, and to then shape the pavlova from there – using this method ensures that your pavlova will have some height.
9. Use a palette knife to shape the sides of the pavlova and to slightly flatten the top. The pavlova will expand and rise once cooked, so shape it to be on the slightly smaller side. 
10. Place the pavlova in the oven and immediately turn the temperature down to 150°C/300°F (without fan).
11. Bake for 1 hour. Do not open the oven door during this time.
12. After 1 hour, turn off the oven and leave the oven door closed so the pavlova can cool down completely. You should leave the pavlova in the oven for at least 2-3 hours, but overnight (12-18 hours) is best.

To Decorate the Chocolate Pavlova

1. Assemble the pavlova just before serving.
2. Whisk the cream until it is thick and soft.
3. Spread the sweetened chestnut cream over the pavlova.
4. Top with the whipped cream.
5. Grate the chocolate over the cream.