Koloche(Slavic Christmas Roll) - cooking recipe

Ingredients

4 c. flour
1 1/2 c. butter
4 egg yolks
1/2 pt. sour cream
1 large fresh yeast
1/2 tsp. salt
3 Tbsp. sugar

Preparation

Mix flour and butter as for pie crust.
Add beaten egg yolks, crumbled yeast, salt, sugar and sour cream.
Mix together lightly. Cover bowl with damp towel and put in refrigerator overnight.
In morning, divide into 3 or 4 pieces and roll out on board with powdered sugar and roll very thin.
Cut in 3-inch squares and fill with nut mixture ( recipe follows).
Roll each square as for jelly roll.
Place on cookie sheet about 1/2 inch apart and brush with egg whites.