Beat the softened butter with the egg, sugar, cinnamon and vanilla sugar until frothy. Mix the flour with the baking powder and salt and add. Carefully stir in the chopped hazelnuts and chocolate drops. Put small heaps of the dough on a baking sheet with a teaspoon. They later turn into round cookies, so make sure there is enough space.
Bake on the middle rack for about 12-14 minutes. Let the cookies cool and store in a tin can.