To make Red Raspberry Crush: Thaw raspberries on countertop at room temperature 30 minutes.

Using rolling pin, gently mash raspberries in sealed bag.

To make tarts: Heat oven to 425° F. Line baking sheet with parchment paper and set aside.

Place strainer over medium bowl; strain Red Raspberry Crush 10-15 minutes, allowing raspberry juice to fall into bowl. Reserve raspberry juice for glaze.

In medium bowl, combine drained Red Raspberry Crush and cornstarch; mix to combine.

Roll out both pie crusts into rectangular shapes and cut each into eight 2 1/2-by-4-inch rectangular pieces. Place rectangular pieces on prepared baking sheet. Add 1-2 tablespoons Red Raspberry Crush to center of each piece and top each with second rectangular piece. Use fork to crimp edges of dough.

Bake 10 minutes, or until crust is golden brown. Remove pastries from oven and allow to cool completely.

To make glaze: In medium bowl, whisk powdered sugar, reserved raspberry juice and vanilla.

Drizzle glaze on cooled pastries and garnish with sprinkles, if desired.