In a large mixing bowl, combine the blueberries, sugar, cornstarch, and lemon juice. Mix well and set aside.
In another bowl, prepare the crumble topping by mixing the flour, brown sugar, and cold butter pieces. Use your fingers or a pastry cutter to combine until the mixture resembles coarse crumbs.
Pour the blueberry mixture into the pie dish. Sprinkle the crumble topping evenly over the blueberries.
Bake in the preheated oven for 45 minutes, or until the topping is golden brown and the filling is bubbly.
Let the pie cool for at least 30 minutes before serving. Enjoy!