Cherry Puff Pastry Pies

INGREDIENTS FILLING 1 1/2 tbsp. cornstarch 1 1/2 tbsp. room temperature water 12 oz. bag frozen cherries (or 1/4 cup fresh cherries, pitted and stemmed) 1/2 c. granulated sugar 1 tsp. fresh lemon juice 1/8 tsp. salt 1 tsp. vanilla extract CRUST 1 box (2 sheets) frozen puff pastry, thawed overnight in the refrigerato 1 large egg, beaten 2 tsp. milk coarse sugar, for...