How To make Pyrizhky(Baked Turnovers)

2 1/2 c Unbleached All-Purpose Flour
1/4 lb Butter

1 Stick
1/2 c Sour Cream
3 lg Egg Yolks
1/2 ts Salt
1 lg Egg White :

Beaten With A
-Little Water For Glazing 1/2 c Coarse Sugar Crystals
-(Optional)
Combine the flour and cold butter in a processor or cut the butter with a pastry cutter into coarse crumbs. Add the egg yolks, salt, and cream and process or knead lightly until the dough forms a ball. Cut in half, wrapping each have in plastic wrap, refrigerate for at least 2 hours or overnight. Roll out half the dough on a lightly floured work surface, to about 1/4-inch thickness. Cut into rounds with a 3-inch cutter or wine glass. Place a spoonful of the
filling on one side of each round, fold the top over, brush with a little of the egg glaze and seal with a fork or pastry cutter for a fancy edge. Place each turnover on a lightly greased or non-stick baking sheet and brush with the glaze then sprinkle with the sugar crystals. Bake in a preheated 375 Degree F. oven for about 20 minutes. Cool on wire racks. NOTE: This is a short dough so a non-stick baking sheet would be the best. If it is not available, brush as little grease on the sheet as possible using a pastry brush or new paint brush.