Preheat the oven to 375°F (190°C)
Peel, core, and slice the apples
Toss the apple slices with sugar, cinnamon, nutmeg, lemon juice, and flour or cornstarch
Let the mixture sit for 10 to 15 minutes
Roll out the pie dough and place it in a pie dish
Add the apple filling to the crust
Dot the filling with butter
Cover with a top crust or lattice if desired
Cut slits in the top crust if using a full top
Brush the crust with egg wash or milk
Sprinkle with sugar if desired
Bake for 45 to 60 minutes
Cover the edges with foil if they brown too quickly
Bake until the crust is golden and the filling is bubbling
Cool before slicing