Preheat the oven to 375°F and line a baking sheet with parchment paper.
In a mixing bowl, combine the diced apples with granulated sugar, cinnamon, and butter. Stir until the apples are evenly coated.
Roll out both pie crusts on a lightly floured surface. Cut each crust into four equal squares or circles.
Place a spoonful of the apple mixture in the center of half the pieces. Drizzle a small amount of caramel sauce over the apples.
Top with the remaining crust pieces. Press the edges together with a fork to seal. Brush the tops with beaten egg.
Sprinkle black sanding sugar over each hand pie. Transfer them to the prepared baking sheet.
Bake for 20 to 25 minutes until the crust turns golden. Let the pies cool for a few minutes before serving.