Preheat oven to 400 degrees Fahrenheit (200 degrees Celsius).

Place the unbaked pie crust into a 9-inch pie plate and crimp the edges.

In a large mixing bowl, toss the sliced apples with granulated sugar, 0.25 cup flour, cinnamon, and lemon juice until evenly coated.

Pour the apple mixture into the prepared pie crust, spreading it into an even layer.

In a separate medium bowl, whisk together 1 cup flour and brown sugar for the topping.

Using a pastry cutter or two knives, cut the chilled butter into the flour mixture until it resembles coarse crumbs.

Sprinkle the crumb topping evenly over the top of the apple filling.

Bake for 45 to 50 minutes until the crust is golden brown and the internal apple juices are bubbling.

Remove from the oven and allow to cool on a wire rack for at least 1 hour to set before slicing.