Beat the butter until frothy; Add sugar, vanilla sugar and the unbeaten egg white and stir the mixture with the hand mixer for about 5 minutes. Stir in the flour, pour the dough into a dough syringe or a piping bag with a serrated nozzle and squirt various shapes (e.g. S-shape) onto a greased tray lightly dusted with flour.
Bake in the preheated oven at 175 ° C for about 15 minutes.