When making sour cherry pie, I cook the cherry filling first.
4 cups sour cherries
1 1/4 cup sugar
4 tsp. cornstarch
1/4 tsp. almond extract
1 Tbsp. sugar to sprinkle over crust
I start with frozen cherries, so I heat them in a saucepan until they are melted and the juice comes out. Mix the sugar and cornstarch together. Add it and the almond extract to the cherries and cook until the liquid clears and thickens. Cool the filling.
2 cups all purpose flour
1 tsp. salt
1 tsp. sugar
1 cup butter, chilled and cut into small pieces
1/2 cup ice water
1 Tbsp. vinegar
Cut the butter into the dry ingredients. Add water and vinegar and bring pastry together. Do not overwork. Divide in two portions. Roll out two rounds of pastry, cutting vents in the top one. Put the bottom pastry in the pie plate, add the filling, and cover with the top pastry.