INGREDIENTS:
1 cup soft butter
3 cups sifted all-purpose flour
1 pkg. active yeast
2 Tbsp warm water
3 egg yolks
1 cup dairy sour cream
1 tsp vanilla extract

FILLING:
1 lb. walnuts
1 cup sugar
3 tsp vanilla extract
1/2 cup milk
Confectioner's sugar

FOR PASTRY: Cut butter into flour. Soften yeast in warm water. Add to flour mixture with remaining ingreditents. Mix throughly and chill a few hours or overnight.

Roll dough to 1/8-inch thickness on floured board and cut in 3-inch squares. Put 1 tsp filling in the center of each square. Moisten edges of pastry with water and pinch corners up and together.

FOR FILLING: Grind walnuts, add sugar, vanilla and milk. Mix well.

Bake on ungreased cookie sheet in 375° oven about 15 minutes. Cool and sprinkle with powdered sugar.