Preparation: Mix the egg yolks with the sugar, cream and vanilla sugar until frothy. Mix flour with baking powder and add. Beat the egg white until stiff and fold in with the lemon zest. Pour the dough into a greased, crumbled Guglhupf pan.
Baking time: Bake 40-50 minutes at 180 ° in a fan oven.
Dust the cooled cake with powdered sugar or cover with a chocolate icing.