Bake a sponge cake: whisk the egg whites until stiff. Gradually add sugar. When the mixture is stiff and glossy and the sugar is completely dissolved, add the egg yolks one by one. Sift the flour , cocoa and baking powder into the egg mixture and mix gently.
Pour the mixture onto a baking tray lined with baking paper. Bake in a preheated oven for about 40 minutes, at 160 C.
Let the sponge cake cool. Prepare an infusion of coffee and cool. Combine with rum.
Prepare the mixture: mix egg yolks, sugar and both flours with a glass of milk. Boil the remaining milk. Pour the prepared mixture over the boiling one and boil.
Cover and let it cool.
Cream the butter until fluffy. All the time mixing, gradually add the pudding. Add nutella to the pudding mixture and mix well.
Soak the sponge cake with the infusion (about 12 tablespoons). Lay out the chocolate mixture. Level it out. Arrange a layer of light cookies. Spread them thinly with plum jam and cover with a layer of dark biscuits.
Whip the cooled cream cheese to stiffness together with sugar and cream-fixes. Spread on top of the cake. Place in the refrigerator, preferably overnight.
Before serving, dust the cake with cocoa and chocolate chips.