For the layers, beat the yolks with half the sugar until you get a light and fluffy cream. Pour in 1/2 the flour, ground walnuts and cocoa.
Transfer the mixture to a greased and floured cake form and bake in a moderate oven. This is the Night part of the cake.
Place the dark cake layer first and syrup it with the cream. Smear the white cake layer with cream, put it on top and then smear the entire cake with cream on top.
If desired, you can cut each cake layer in half to get a total of 4 layers.