Preheat the oven to 425°F.

In a large bowl, combine the diced apples and lemon juice. Add the granulated sugar, cinnamon, nutmeg, and flour. Toss until the apples are evenly coated.

Roll out one pie crust on a lightly floured surface. Using a round cutter or a glass, cut out circles about 4 inches in diameter. Repeat with the second pie crust.

Place half of the circles on a baking sheet lined with parchment paper. Spoon about 2 tablespoons of the apple mixture onto the center of each circle.

Top each filled circle with another crust circle. Press the edges together to seal, then crimp with a fork. Cut a few small slits in the top of each pie to allow steam to escape.

Brush the tops of the pies with the beaten egg and sprinkle with coarse sugar.

Bake for 20-25 minutes or until the pies are golden brown. Let cool for a few minutes before serving.