How to cook
For the egg cream: make a mix of egg yolks, flour, vanilla, lemon rind and 2/5 cup (100 ml) of milk. Heat the rest of the milk with the sugar and when it boils, add the mixture while constantly stirring, and when thickened, remove it from the heat. Leave it aside to cool completely.
For the cocoa layer, crush the cocoa biscuits into a bowl and add the melted chocolate. Mix well with your hands. Leave aside.
For the lemon layer, crush the lemon biscuits into a bowl and add the melted butter and lemon zest. Mix well with your hands. Leave it aside. After all the components of the cake are ready, you can assemble the cake in a form with a removable sides, about 9″ (23 cm) in diameter.
At the bottom of the form, add half of the lemon biscuits and press well in order to obtain a solid foundation. Add half of the egg cream, smooth it out and put half of the strawberry cream on top. Smooth and press down well.
Arrange cocoa biscuits on top, press them gently into the cream, but do not let them sink in completely. Add the remaining egg cream. Smooth out well, and add the rest of the strawberry cream. Smooth and press down nicely again. Finish it off with remaining lemon biscuits.
Even out the top and press down on the cake lightly. Put it in in the refrigerator for 2-3 hours to harden well; be sure to cover the cake, so it doesn't absorb any odors from the refrigerator. Swipe a knife around the edge of the form and then open it. For decoration, beat the cream and divide it in 2.
Leave half of it as is and mix the other half with the cocoa. Smear the cake on all sides with the cream one and make cocoa rosettes with the other on the side of the cake using a pastry bag.
Add strawberry jam on top of the cake. Decorate with chocolate bonbons and the set aside biscuits.