Directions

Preheat your oven to 375°F (190°C).
Fit the pie crust into a 9-inch pie dish, trimming any excess dough around the edges.
In a large bowl, combine the blueberries, granulated sugar, cornstarch, lemon juice, and vanilla extract. Mix gently until the blueberries are evenly coated, then pour the mixture into the prepared pie crust.
In another bowl, mix together the flour, oats, brown sugar, cinnamon, and salt. Add the chilled, cubed butter and use your fingers or a pastry cutter to blend until the mixture resembles coarse crumbs.
Sprinkle the crumble topping evenly over the blueberry filling.
Place the pie on a baking sheet to catch any drips, then bake in the preheated oven for 45-50 minutes, or until the filling is bubbly and the topping is golden brown.
Allow the pie to cool for at least 2 hours before serving to let the filling set.
Variations & Tips

For a twist, you can add a handful of chopped nuts, such as pecans or almonds, to the crumble topping for extra crunch. If you have picky eaters, try replacing half of the blueberries with sliced strawberries or raspberries for a mixed berry version. You can also make this pie gluten-free by using a gluten-free pie crust and replacing the flour in the topping with a gluten-free flour blend.