Mix flour with baking powder and sift into a bowl. Add sugar, vanilla sugar, egg, rum and butter in flakes. Process the ingredients with the dough hook of the hand mixer into a smooth dough. Knead in the nuts and oatmeal.
Place the dough with two teaspoons in walnut-sized piles on a baking sheet lined with baking paper, leaving enough space between the dough piles.
Preheat the oven to 180 ° C (fan oven: 160 ° C). Bake for 10-15 minutes.
Let the cookies cool down. Dip into the melted cake icing / chocolate and allow to dry.