Preheat oven to 160 degrees hot air.
Mix sugar, vanilla sugar, salt and butter until very fluffy. Then add the egg yolks.add flour and quickly mix to a dough.
Leave to rest in a cool place for 2-3 hours.
Then form small doughnuts from the dough. Place them on a baking tray lined with baking paper.
Make a small indentation in the middle of the doughnuts and fill them with currant jam.
Bake for approx. 10-12 minutes.
Decorate the cooled cookies with sugar glaze and add a little jam before serving.