How to make
Heat the milk. Then, crumble the biscuits finely and pour the milk over them.
Beat the softened butter with the sugar.
Separate the egg yolks from the whites and place the yolks in the butter mixture. Pour the biscuits in as well. Add the cocoa and walnuts. Stir well in order to get a smooth mixture.
Transfer the mixture to a cake form.
Beat the egg whites into snow. Caramelize the sugar and add it to the whites.
Form an egg white hat on top of the cake and keep it in the fridge until it's time to serve.