Knead all ingredients into a smooth dough. Wrap the dough in foil and let it rest in the refrigerator for about 1 hour.
Preheat the oven to 180 ° C top / bottom heat (convection: 160 ° C).
Then take the dough out of the refrigerator in portions, roll out about 1/2 cm thick on a floured work surface and cut out with molds as desired. Now mix the egg yolk with 1 tablespoon of water and brush the biscuits with it. Then decorate with e.g. sugar sprinkles or other heat-resistant decoration as required.
Put the cookies in the hot oven and bake golden yellow in the middle for about 13 minutes.