Separate the eggs. Mix the sugar, vanilla sugar and egg yolk until foamy. Mix the baking powder into the ground nuts and stir into the sugar-egg mixture. Add the softened butter, rum and ground chocolate blocks. Mix everything well. Make egg whites from the 5 egg whites and fold into the dough.

Pour the dough into a greased 26mm springform pan and bake in a preheated oven at 150 degrees top/bottom heat for 60 minutes.

When the base has cooled, beat the cream with 1 teaspoon of sugar and 1 packet of cream stiffener until stiff and spread onto the base using a cake ring. Chill the cake for at least an hour and then pour enough eggnog onto the cream until the cream is completely covered. Chill for another hour and then remove the cake ring.