Roll out pie crusts and cut out 16 heart shapes. Transfer to a baking sheet and chill for 30 minutes.
Combine berries, sugar, and salt in a saucepan set over medium heat. Bring to a boil and simmer for 10 minutes. In a small bowl, whisk together water and cornstarch until smooth. Add cornstarch mixture to berries and cook for 2 minutes or until mixture thickens slightly. Remove from heat and stir in vanilla extract. Transfer mixture to refrigerator and chill for 30 minutes.
Preheat oven to 400°F. Lay 8 dough hearts on a parchment lined baking sheet. Place 1-2 tablespoons of berry filling into center of each dough heart. Top with remaining dough hearts and crimp with a fork to seal. Use a sharp knife to cut a small vent on the top of each hand pie. Brush tops lightly with beaten egg and bake for 18-20 minutes or until dough is golden brown and filling is hot and bubbling. Transfer hand pies to a wire rack to cool completely before glazing.
While pies bake, make glaze by beating together cream cheese, white chocolate and powdered sugar until smooth. Add milk a tablespoon at a time until glaze is thick but pourable. Glaze tops of pies and decorate with sprinkles if desired.