Heat oven to 350°F. Lightly spray cookie sheet with cooking spray.
In 2-quart heavy saucepan, heat cranberries, orange juice and granulated sugar to boiling. Boil 2 to 3 minutes or until cranberries begin to pop. Remove from heat; beat in cornstarch with whisk. Return to heat, and boil 2 to 3 minutes longer or until mixture is very thick. Remove from heat; add chopped apple. Stir until well combined.
Using 3-inch round cutter, cut 12 rounds from each crust, rerolling and shaping as necessary. Place 12 rounds on cookie sheet. Spoon 1 heaping tablespoonful filling on center of each of 12 rounds.
Cut small hole in center of each of remaining 12 rounds. Place 1 on top of each round with filling. Pinch edges to seal. Lightly brush tops with milk, and top with coarse sugar.
Bake 15 to 20 minutes or until golden brown. Serve warm or at room temperature with ice cream.