Mix the flour, almonds, egg, vanilla sugar, sweetener and vanilla flavor in a bowl. Add the cold butter in flakes. Process everything into a smooth dough. Let rest in the refrigerator for 1-2 hours.
Shape the dough into small croissants on a floured work surface, tapering to a point at the end. Place on a baking sheet lined with baking paper and bake in the oven preheated to 175 ° C for about 15-18 minutes.
Roll in powdered sugar while it is still hot. Attention! they break easily!
The croissants taste particularly good and vanilla when you mix ground vanilla with the powdered sugar.