Whisk the flour, sugar, and salt for the crust. Cut in the cold cubed butter until pea-sized pieces remain, then add ice water one tablespoon at a time until the dough just comes together.

Shape the dough into a disk, wrap it, and chill for at least 30 minutes. Roll it into an approximately 12-inch circle, fit it into a 9-inch pie plate, crimp the edges, and refrigerate while preparing the filling.

Toss the sliced apples with granulated sugar, brown sugar, flour, lemon juice, cinnamon, nutmeg, and salt. Let the mixture stand for about 10 minutes so the juices begin to release.

Mix the streusel flour, brown sugar, cinnamon, and salt. Work in the melted or softened butter until coarse, moist crumbs form.

Mound the apples slightly in the chilled crust and sprinkle the streusel evenly over the top. Bake at 400°F (200°C) for 20 minutes, then reduce the oven to 375°F (190°C) and bake for another 35-45 minutes.

Continue baking until the topping is golden and the filling is visibly bubbling in the center. Loosely cover the crust or pie with foil if it browns too quickly, then cool for at least 2-3 hours before slicing.