In a large bowl, combine diced apples, granulated sugar, flour, cinnamon, nutmeg, and lemon juice. Toss to coat evenly.

In a separate bowl, whisk together flour and salt.

Cut in the cold butter using a pastry blender or your fingertips until the mixture resembles coarse crumbs with some pea-sized pieces of butter.

Gradually add ice water, one tablespoon at a time, mixing until the dough just comes together. Be careful not to overmix.

Divide the dough in half, flatten each half into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes.

Preheat your oven to 375°F (190°C). Line baking sheets with parchment paper.

On a lightly floured surface, roll out one disk of dough to about 1/8-inch thickness.

Cut out circles using a 4-inch round cutter. Reroll scraps as needed.

Spoon about 2-3 tablespoons of the apple filling onto one half of each circle, leaving a small border.

Moisten the edges of the dough with water and fold the other half over the filling to create a half-moon shape. Crimp the edges with a fork to seal.

Place the hand pies on the prepared baking sheets. Cut a few slits in the top of each pie to allow steam to escape.

Whisk together the egg and water for the egg wash. Brush the tops of the hand pies with the egg wash.

Bake for 20-25 minutes, or until golden brown and bubbly.

Let cool on the baking sheets for a few minutes before transferring to a wire rack to cool completely.