Crumble flour (mixed with yeast) with butter, add salt and work with milk to form a smooth dough - wrap this in a cloth and place in cold water for an hour.
Then roll out in portions on a well-floured board, cut out biscuits and bake in a preheated oven at 160 ° for about 10 minutes.
Roll the hot biscuits in the icing sugar / vanilla mixture.