How to cook
To the egg whites, add the sugar, flour, milk, stir and boil until thickened.
Add the gelatin. Leave it to cool, while stirring so it doesn't form a crust.
Add the vanillas. Beat the yolks and add them to the cream. Set aside half of it and put the cocoa in one half. Add the lemon zest to the other.
In a wet cake form, pour in the cream, then the cocoa cream on top. Leave it in the freezer to harden.