01 - Heat the oven to 375°F and position the rack in the middle.
02 - Place the pie crust into a 9-inch pie dish. Trim excess pastry and flute the edges as preferred. Set aside.
03 - In a large bowl, combine apples, granulated sugar, brown sugar, flour, cinnamon, nutmeg, salt, lemon juice, and vanilla extract. Toss thoroughly to coat the apples evenly.
04 - Transfer the apple mixture into the prepared crust, spreading into an even layer.
05 - In a medium bowl, mix flour, brown sugar, granulated sugar, cinnamon, and salt. Add cold cubed butter and blend with a pastry blender or fingers until coarse crumbs form.
06 - Sprinkle the crumble topping evenly over the apple filling.
07 - Place the pie on a baking sheet to catch drips and bake for 45 to 50 minutes until the topping is golden and filling bubbles. If browning too fast, tent loosely with foil.
08 - Remove from oven and cool for at least one hour to allow the filling to set before slicing.