Slice apples and mix with 3 tbsp. sugar. Poach under a low heat (do not boil). Allow to cool. Beat 1 egg with 1/2 cup sugar, salt and vanillin. Add 2 tbsp. sour cream and butter (soft). Pour in the sifted flour and baking powder, and knead dough. Make the pouring. Mix 2 eggs, 2 tbsp. sugar, vanilla sugar, 6 tbsp. sour cream and starch in a cup. Divide the cooled dough into two unequal parts. Distribute the most part of dough along the baking dish by hands and form the sides. Fill with the pouring and lay the apple filling atop. Roll out the smaller part of dough into a thin layer. Make heart-shaped figurines with a plunger cutter and put them on top of the pouring with apples. Bake in a hot oven at 180 °C for 40 minutes until golden brown. After it has cooled, sprinkle with powdered sugar.