Mix the egg yolks with the sifted sugar, vanilla sugar, vanilla flavor, bitter almond oil and water until frothy. Then stir in the oil very slowly. Sift the flour and mix with the baking powder, mix with the egg yolk mixture. Beat the egg whites until stiff and fold in.
Divide the dough in two and then fold the chocolate under half. First pour the light-colored, then the chocolate dough into a greased, floured or breadcrumb-lined bundt pan.
Bake in the preheated oven at 175 ° C (top / bottom heat) for about 60 minutes. Let the Gugelhupf cool, then turn it out onto a grid and sprinkle with powdered sugar.