Serbian Nut Roll/ Recipe Of My Great Grandmother Sophie Kochka - cooking recipe

Ingredients

To freeze wrap in plastic wrap and then foil and freezer bag.
Filling:
4 cups finely grond walnuts (1 pound shelled)
6 large egg whites
1 1/2 cups sugar
Dough: (works better if everything is at room temp)
1 stick butter
4 large eggs (1 egg is used for egg wash)
1/2 cup sour cream or plain yogurt
3 tbs. sugar
3 1/2 cups (or more) all purpose flour
2 pkgs. powered yeast (5 tsp.)

Preparation

For the filling:
Beat egg whites until stiff. Gradually add sugar and beat until stiff again. Fold egg whites into ground walnuts and set aside.
For the dough:
Proof yeast: Sprinkle yeast and a pinch of sugar over 2 1/2 tbs. warm water in a small warmed bowl ( if it dosen't foam in 10 min, throw away and use fresh yeast)
Cream butter and sugar, add one egg at a time and beat until 3 eggs used. Add sour cream or plain yogurt and dissolved yeast, add flour a little at a time and blend well. Turn onto floured surface and knead until smooth (add more flour as needed for kneading and rolling).
Divide into 4 balls, cover dough and allow to rest approx. 15 min. Roll out one at a time to approx. 12 in. or more in diameter circle (dough will be very elastic). Spread 1/4 filling evenly and out to the edge. Roll like a jelly roll towards you, Flour ends and press together.
For Traditional Serbian rolls, shape into a cresent(half moon).
Place on a greased cookie sheet (with edges) two rolls to a cookie sheet. Cover with a clean non-textured (cotton) dish towel and let rise in a warm place for 1 hour (continue with other rolls).
Bake 1 cookie sheet at a time. Before baking, brush rolls with remaining egg (beat egg with 1/4 cup water). Bake at 350 degrees F, Cool completely on rack.