Take the butter out of the refrigerator in time to make it nice and soft.
Then separate the eggs into egg yolks and whites. You put the egg whites in a bowl and beat them to snow. Once the snow starts to firm up, add the granulated sugar and keep beating until the snow is really nice and stiff.
It’s time to preheat the oven to 180 °C.
Now put the butter in another (not too small) pastry bowl and mix until it becomes fluffy, that is, thick.
Then add the icing sugar, vanilla sugar and egg yolks and continue mixing until everything is fluffy.
Now weigh out the flour and mix it with the baking powder. Add half of the flour to the yolk mixture, pour in the milk and stir vigorously.
Now put away the mixer and, using a whisk with your hand, stir in a little flour and snow alternately, stirring gently and repeating this process until everything is used up.
Next, in a very small saucepan, melt a good tablespoon of butter over low heat and brush the bundt pan with it so that everything is really well covered with fat. Keep in mind that the Gugelhupf will probably stick in all the places that are not coated or are poorly coated when you turn it over later.
Pour one third (if you want more cocoa in the Gugelhupf) or half of the dough into the mold. In the rest you sieve