How to cook
Whip the butter with the sugar for 15 min, then add the yolks 1 at a time, stirring nonstop.
Gradually add the flour and knead a dough, form cookies from it.
Dip them in the whipped yolks and sprinkle with finely crushed almonds or crystallized sugar. Bake them in the oven about 30 min, being careful not to burn them.