Pastry-In a large mixing bowl stir together the flour and salt. Using a pastry blender, cut in shortening until pieces are pea size. Set aside.
Lightly beat egg yolk in a glass measuring cup. Add enough milk to egg yolk to make 3/4 cup total liquid; mix well. Stir egg yolk mixture into flour mixture; mix well. Shape one third of dough into a ball; set aside.
Form remaining two thirds of dough into a ball. On a lightly floured surface use your hands to flatten dough. Roll dough from center to edges into an 18x12-inch rectangle. Wrap pastry around the rolling pin; unroll into a 15x10x1-inch baking pan (pastry will hang over edges of pan).
Preheat oven to 350. In a large bowl combine sugar and cornstarch. Stir in apricots and cherries. Spoon into the crust.
Roll the remaining dough into a 16x11-inch rectangle; place over fruit. Bring bottom pastry up and over top pastry. Seal edges with the tines of a fork. Prick top pastry over entire surface with the fork.
Bake about 40 minutes or until golden brown. Cool in pan on a wire rack. Drizzle with vanilla glaze.Serve warm or cool. Makes 25 bars. Glaze-In a small bowl stir together powdered sugar and vanilla, now stir in enough milk to make a glaze of drizzling consistency.