First, preheat the oven to 160 °C hot air.
Knead the sugar, vanilla sugar, butter and salt. Add the egg and the liqueur and continue kneading. Mix the flour and baking powder and knead into the dough.
Let the dough rest in the refrigerator for 2-3 hours.
Cut out stars. For half of the stars, do not cut out an inner star.
Bake on a baking sheet lined with parchment paper for about 10-12 minutes in the oven.
Sprinkle the stars with the inner star cut out with powdered sugar. Spread the apricot jam on one cookie at a time.
Place a sugared cookie on top of the jam-covered one.