For the vanilla crescents, knead butter, sugar, flour, egg yolks and almonds into a dough and wrap in plastic wrap. Chill in an icebox for about 1 hour. Preheat oven to 180°C / hot air. Form rolls of dough about 2 cm thick and cut about 50 pieces of the same size. Form croissants from the dough pieces and place on a baking tray. Bake in the oven for 10-15 minutes. Mix the sugar with the vanilla sugar and roll the still hot vanilla crescents in it.