Blueberry Crumb Pie

Preheat oven to 425 degrees F. Meanwhile, in a large bowl, toss blueberries with 1/2 cup sugar and 2 tablespoons flour until coated. Arrange berries on prepared piecrust and sprinkle with lemon juice. In a medium bowl, using a pastry blender or your fingers, combine butter and remaining sugar and flour until crumbly and butter pieces are the size of small peas. Using your hands, spread crumble mixture evenly over blueberries. Place pie on a rimmed baking sheet (to protect oven from spills) and bake for 15 minutes. Reduce heat to 350 degrees F and continue baking until topping is light golden brown, 35 more minutes. Transfer pan to a wire rack for 3 to 4 hours to cool and allow pie filling to set.