1. Preheat the oven to 170ºC and line the base of 2 x 20cm cake tins with baking paper – do not grease.
2. In a jug or small bowl, stir together the cocoa, oil, milk, vanilla and egg yolks.
3. Sift the flour, baking powder, salt and 1 cup of the sugar together in a large baking bowl. Make a well in the centre and pour in the cocoa mixture; stir together loosely.
4. Working quickly and using electric beaters, beat the egg whites and vinegar together in a clean bowl until foamy. Slowly add the remaining sugar until a soft meringue-like consistency is reached.
5. Stir a large spoon of the egg white mixture into the flour and cocoa mixture then fold through remaining egg whites. Divide mixture equally between prepared tins.
6. Bake in the preheated oven for 17-20 minutes. When cooked, the cakes will spring back when lightly touched in the centre. Leave in tins until completely cool before turning out.

Tips: Not greasing the sides of the cake tin allows these light and airy cakes to climb higher up the sides of the pan.

Double the recipe for up to 4 layers!

Assembly

1. Lightly whip mascarpone, cream and icing sugar together till stiff peaks form.
2. Take a layer of sponge and spoon on a generous layer of the mascarpone cream mix. Lay strawberries on the cream.
3. Place another layer of sponge and repeat for as many layers as you have.
4. Add the final layer and top with the remaining cream, sliced strawberries and grated chocolate. Dust with icing sugar.