Mix 2½ cups flour and ½ teaspoon salt. Cut in 1 cup cold cubed butter with a pastry cutter until pea-sized crumbs form. Add 6-8 tablespoons ice water, 1 tablespoon at a time, until dough just holds together. Divide in half, flatten into disks, wrap in plastic, and chill at least 1 hour.
2.5 cups all-purpose flour, 0.25 teaspoon salt, 1 cup unsalted butter, 6-8 tablespoons ice-cold water
Peel, core, and slice 6-7 Granny Smith apples into ¼-inch pieces. Toss with ¾ cup granulated sugar, 2 tablespoons cornstarch, 1½ teaspoons cinnamon, 1 tablespoon lemon juice, and optional nutmeg in a large bowl until evenly coated. Let sit 10 minutes to release juices.
6-7 medium Granny Smith apples, 0.75 cup granulated sugar, 2 tablespoons cornstarch, 1.5 teaspoons ground cinnamon, 1 tablespoon lemon juice, 0.25 teaspoon nutmeg
Preheat oven to 375°F. Roll one dough disk on floured surface to a 12-inch circle and fit into a 9-inch pie dish. Trim edges, line with parchment paper and pie weights or dried beans. Bake for 10 minutes. Remove weights and parchment, then cool crust 5 minutes.
2.5 cups all-purpose flour, 1 cup unsalted butter
Pour apple filling into blind-baked crust. Roll second dough disk to a 12-inch circle. Cut into strips for lattice top or leave whole and cut 4-5 vent slits. Place over filling, trim and crimp edges, and brush top with beaten egg wash.
6-7 medium Granny Smith apples, 1 large egg
Bake at 375°F for 45-50 minutes until crust is golden brown and filling bubbles through vents. Cover the edges with foil after 30 minutes if browning too fast. Cool pie on a wire rack for 2 hours before slicing so the filling sets.
