In the bowl of the food processor, combine the flour, brown sugar, butter and granulated sugar. Pulse until combined. Remove to a small mixing bowl and using the back of a large spoon, press some of the topping together to form large chunks. Refrigerate until ready to use.
To assemble the pie, pour the blueberry mixture into the blind baked pie crust. Top with the crumble mixture spreading evenly.
Bake on the foil lined baking sheet at 375°F for 1 hour. After 30 minutes, cover the pie with foil if starts to brown too quickly.
Once the filling bubbles and the pie is golden brown, remove from the oven and allow to cool to room temperature.
Store leftovers in the refrigerator.