Beat the egg yolks with sugar, vanilla sugar and the orange peel until a thick foam. Add flour, baking powder and nuts and stir in. Beat the egg white until stiff and fold in carefully. Fill into a greased springform pan (26 cm diameter) and bake at 180 degrees for about 50 minutes. Let cool a little.
Then place the cake on a plate with a slightly higher rim.
Bring the ingredients to the boil briefly together for soaking and distribute evenly over the cake with a spoon. Let it steep for at least a day so that all of the liquid can soak into the cake.