For the dough mix the soft butter with powdered sugar and vanilla. Add the egg and flour quickly knead a soft dough. Put it in a plastic bag and leave it in the refrigerator for 1 hour. For the cherry filling boil for a few minutes as you relax your juices. Add vishnovkata. You can replace it with cherry brandy or other alcohol of your choice. In a bowl mix the sugar with starch and pour in sour cherries. According to taste, you can put more or less sugar. Cook for a minute, two until thickened sauce. Allow the fruit to cool before putting them in the pie. Remove the dough from the refrigerator and leave part of the dough to cover the pie. Roll majority on baking paper or plastic foil, to more easily transfer the dough into the pan. Bring the resulting oil crust in pie pan 25 cm with paper / fthe oil, turn it inside and remove the paper. Remove and excess dough from the edges of the mold. Pierce with a fork. Pour the cooled cherries them evenly. remaining dough, roll out and cut into strips with which to cover the pie. Brush the pie with lightly beaten egg-white and sprinkle with granulated sugar. Of egg white dough becomes much more crispy than if it is coated with whole egg. Bake the pie in a preheated 180C oven for about 25 minutes.