Mix the butter, sugar, vanilla sugar and egg yolks together until frothy. Then add the milk and gradually add the flour. Mix the baking powder with the last part of flour and stir in as well. The cinnamon can be added last as desired. Beat the egg white until frothy and fold in.
Preheat the waffle iron and then bake the batter in it.
Tip:
I always do it so that the waffles are really soft: I put the batter in the iron, the device on the highest level (5 for me), so that the waffles brown very quickly, but remain very soft inside. If they`re in for too long, they get tough quickly.