How to make
Beat the egg yolks with the softened butter and while beating constantly, add the powdered sugar and flour. Of the resulting dough, shape balls the size of a walnut.
Roll each ball in the beaten into snow egg whites, then in the mixed chopped walnuts and granulated sugar.
Arrange them in a baking dish, covered with baking paper and put them to bake in a preheated 360°F (180 °C) oven until ready.