Combine all filling ingredients except cornstarch in a large saucepan, mashing the fruit with a potato masher (or a fork if you don't have one).

Bring to a boil, stirring frequently, and boil for approximately 1 hour.

Let cool.

Preheat oven to 400 F.

Line baking sheet with parchment paper.

Roll out pie crusts and cut into 3" circles.

Brush the edges of each circle with egg, then brush the full circle with butter and sprinkle sugar on top of the butter.

Pinch the top center of each circle tightly, till well sealed. Then pinch the bottom left and right of the circles the same way, forming a triangular pouch.

Combine 1 cup of the sangria mixture with cornstarch.

Spoon filling into the center of each triangle, filling the pouch.

Bake 15-18 minutes.

Let cool.