Involved dough strained cottage cheese, flour and the butter, which is allowed to stand for 1 hour in the cold. Roll out the crust thickness 0.5 cm, which cut squares with length 8 cm. In the middle of each square put jam, the edges are covered up with white (to avoid leakage jam when baking) and is folded in a triangle. Spread top with egg yolk and bake in a moderate oven. Sprinkle with powdered sugar.