Peel the peaches with a vegetable peeler, then pit them and cut them into 1/2-inch pieces (you should have about 1 cup). Melt the butter in a medium skillet over medium heat. Add the peaches, sprinkle with the brown sugar and cornstarch and stir to combine. Cook, stirring constantly, until the peaches are softened and starting to fall apart, 4 to 6 minutes. Stir in the raspberries and preserves, and cook for 1 minute. Remove from the heat, and stir in the lemon juice. Transfer the filling to a medium bowl, and let cool completely, about 30 minutes. Meanwhile, position a rack in the center of the oven, and preheat to 425 degrees F. Line a baking sheet with parchment paper. Let the dough rounds soften at room temperature for 10 to 15 minutes.
Cover one of the dough rounds with a kitchen towel. Unfold the other on a lightly floured surface, and cut into quarters with a sharp knife. Cover 3 quarters with a kitchen towel. Brush the border of the remaining quarter with the egg wash, and put 2 heaping tablespoons of the filling just off-center on the dough. Fold the quarter in half, and press out any air with your fingers, leaving a 1/2-inch border around the filling. (These pies are pretty full. If a little of the filling squeezes out the edges, simply brush it away and add it back to the bowl of filling.) Press the edges with a fork to seal them, and brush the top of the pie with the egg wash. Cut three 1/2-inch slits in the top (to allow steam to escape during baking), and transfer the pies to the prepared baking sheet. Repeat with the remaining dough and filling. The pies won't spread, but make sure they don't touch.
Bake the pies, rotating the baking sheet once halfway through for even cooking, until they're golden brown and the filling is bubbly, 14 to 16 minutes. Let cool completely on a wire rack before serving.
You can freeze the uncooked pies for up to 2 weeks. Thaw, then bake as per the recipe directions.
Copyright 2014 Cooking Channel, LLC. All rights reserved.