Prep the oven and crust. Heat the oven to 425°F (220°C).
Place the chilled pie shell on a baking sheet lined with parchment for easy cleanup. Keep it in the fridge while you prep the filling.
Peel and slice the apples. Peel, core, and slice apples into 1/4-inch slices. You want a mix of firm-tart and firm-sweet apples for depth of flavor and texture.
Toss the filling. In a large bowl, combine apples with granulated sugar, brown sugar, lemon juice, cinnamon, nutmeg, cloves (if using), salt, and cornstarch.
Stir until every slice is evenly coated. Let sit 5–10 minutes to start drawing out juices.
Make the crumb topping. In another bowl, mix flour, brown sugar, granulated sugar, cinnamon, and salt. Add the cold butter cubes.
Using a pastry cutter or your fingertips, work the butter into the dry ingredients until coarse crumbs form with some pea-sized bits. Stir in nuts if using. Chill the topping while you assemble.
Fill the crust. Spoon the apple mixture into the chilled pie shell, mounding it slightly in the center.
If there’s a lot of liquid at the bottom of the bowl, leave most of it behind to avoid a soggy pie.
Add the crumb topping. Sprinkle the crumb mixture evenly over the apples, pressing gently to help it adhere. Try to cover the fruit completely.
Bake hot to set the crust. Bake at 425°F for 15 minutes to set the bottom crust and kick-start the apples.
Reduce heat and continue baking. Lower the oven to 350°F (175°C). Bake 35–45 minutes more, until the topping is deep golden and the filling is bubbling through the crumbs near the center.
If the crust edge browns too fast, shield it with foil.
Check doneness. Pierce the center with a knife—it should meet little resistance. If apples feel firm, bake another 5–10 minutes. Don’t pull it early; underbaked apples are the top complaint with fruit pies.
Cool before slicing. Let the pie cool at least 2–3 hours on a rack.
This allows the juices to thicken so slices hold together. Warm is great; hot-and-runny is messy.
Serve. Slice and serve as is, or add vanilla ice cream or lightly sweetened whipped cream. A drizzle of caramel never hurts.