In a mixing bowl, combine the yeast with 1 cup sour cream; set aside for 10 minutes. Add butter and mix well. Add the egg, oil, and vinegar and mix well. Add the sifted flour gradually and continue mixing. Knead dough for about 15 minutes until smooth and firm so that it does not stick to your hands. Gather dough into a ball and cover with plastic wrap. Refrigerate the dough overnight. To make the filling, mix together 1 cup of the melted butter and 2 cups flour. Add 1-1/4 cups sugar and 1/2 teaspoon vanilla; stir constantly for 1 minute, so that the mixture does not stick to your hands and becomes smooth and even. Set aside.
Armenian RecipesPreheat oven to 350 degrees F. Remove dough from the refrigerator; divide it into 8 equal balls. Place each ball on a lightly floured board. Roll each ball out to a rectangle measuring 10-by-6 inches, or as thin as possible with the aid of rolling pin. Paint each rectangle with melted butter. Spread 1/4 cup filling into the center of each rectangle and roll out the filling over it with the aid of a rolling pin. Fold in about 1/2 inch of the rectangle on each side. Roll up dough into a cylinder. Place rolling pin on pastry roll and flatten slightly lengthwise. Cut the roll diagonally with a sharp knife or serrated knife into 2-inch equal slices. Place pastry about 2 inches apart on a lightly floured baking pan. (Be careful not to spill out any filling.).
Paint the surface of each pastry with the glaze (mixture of beaten egg and brown. Place baking pan in the oven and bake for 15 to 30 minutes, or until golden brown. Remove the baking pan from oven and allow the pastries to cool.