Follow these simple steps to create your delicious Mini Apple Pies:

1. Prepare the Crust: In a large bowl, combine the flour, salt, and sugar. Add the cold, cubed butter and mix until the mixture resembles coarse crumbs.
2. Add Water: Gradually add the ice water, one tablespoon at a time, mixing until the dough just comes together. Avoid over-mixing.
3. Chill the Dough: Divide the dough in half, shape into discs, wrap in plastic wrap, and refrigerate for at least 30 minutes.
4. Preheat Oven: Preheat your oven to 375°F (190°C).
5. Prepare the Filling: In a large bowl, mix the diced apples with granulated sugar, cinnamon, nutmeg, lemon juice, and cornstarch. Toss until well combined.
6. Roll out Dough: On a lightly floured surface, roll out each disc of dough to about 1/8 inch thick. Using a round cutter, cut out circles for the pie crusts.
7. Assemble Pies: Place dough circles into a greased muffin tin, pressing gently to fit. Fill each crust with about 1-2 tablespoons of the apple filling.
8. Top Crusts: Using smaller dough circles, place over the filling to cover. Crimp the edges to seal. Cut small slits in the top to allow steam to escape.
9. Apply Egg Wash: Beat the egg and brush it over the top crusts for a nice golden color.
10. Bake: Bake in preheated oven for 25-30 minutes or until golden brown.
11. Cool the Pies: Remove from the oven and allow the pies to cool in the tin for about 5-10 minutes before transferring them to a wire rack.

With these straightforward instructions, you can confidently create incredible Mini Apple Pies!