Preheat oven to 375°F.
Fit pie crust into the pie plate.
In a large bowl, mix sliced apples, lemon juice, both sugars, flour, cinnamon, and nutmeg. Pile into crust.
Prepare to top: In a medium bowl, with a pastry blender or a fork, mix flour, both sugars, and butter until coarsely crumbled. Sprinkle evenly over apples.
Bake at 375°F for 50 minutes. (If your crust gets too brown early on, cover the edges of the pie crust with tin foil and continue baking)
After you've baked the pie, let the pie cool for around 15 minutes, then serve with whipped topping, a scoop of vanilla ice cream, or as is! Store leftovers in the refrigerator, covering the pie with plastic wrap or aluminum foil.