1. Make the Crust:

– In a large bowl, mix together the flour, sugar, and salt.

– Add the cubed cold butter and use a pastry cutter or your fingers to work the butter into the flour mixture until it resembles coarse crumbs with pea-sized chunks of butter.

– Gradually add ice water, one tablespoon at a time, and mix until the dough just comes together. Be careful not to overwork it.

– Divide the dough into two balls, flatten each into a disc, wrap in plastic wrap, and refrigerate for at least 30 minutes.

2. Prepare the Apple Filling:

– Peel, core, and slice the apples into thin slices.

– In a bowl, combine the apple slices, granulated sugar, lemon juice, cinnamon, nutmeg, and flour. Stir until the apples are evenly coated.

3. Assemble the Mini Pies:

– Preheat the oven to 375°F (190°C).

– Roll out one of the dough discs on a lightly floured surface to about 1/8-inch thickness.

– Use a round cookie cutter or a drinking glass (about 4 inches in diameter) to cut out circles of dough. These will form the base of your mini pies.

– Place the dough circles into muffin tin cups, pressing gently to fit.

4. Fill the Pies:

– Spoon the apple mixture into each mini pie crust, filling each one generously.

– Dot the filling with small pieces of butter.

– Roll out the second dough disc and cut out more circles to form the tops of the pies. Place a top crust over each pie and crimp the edges to seal. You can also make a lattice crust if you prefer.

– Beat the egg and brush it over the top crusts for a golden finish. Sprinkle with coarse sugar for a nice texture.

5. Bake:

– Bake the mini apple pies in the preheated oven for 30-35 minutes, or until the crust is golden brown and the filling is bubbling.

– Let the pies cool slightly before serving.