Prepare the berries by rinsing the blueberries, hulled and sliced strawberries, and rinsed raspberries. Place all berries in a large mixing bowl.
1 box store-bought or homemade pie crust, 2 cups blueberries, 2 cups strawberries, 1 cup raspberries
In a saucepan, combine the sugar and cornstarch, then whisk in the vanilla extract and 1 tablespoon water to create a smooth mixture. Cook over medium heat, stirring constantly, until the mixture begins to thicken and turns translucent, about 2-3 minutes. Remove from heat.
3/4 cup granulated sugar, 2 tablespoons cornstarch, 1 teaspoon vanilla extract, 1 egg egg
Pour the hot thickened mixture over the berries, gently folding with a silicone spatula until the berries are evenly coated and the mixture is combined. Let the filling cool slightly for about 5 minutes.
1 box store-bought or homemade pie crust, 2 cups blueberries, 2 cups strawberries, 1 cup raspberries, 3/4 cup granulated sugar, 2 tablespoons cornstarch
While the filling cools, preheat the oven to 375°F (190°C). Roll out the pie crust on a floured surface to fit a 9-inch pie dish. Transfer the crust to the dish, trimming any excess overhang.
2 cups blueberries
Pour the berry filling into the prepared crust, spreading evenly. Cover with a top crust or create a lattice design if desired. Brush the edges with beaten egg for a golden finish, then cut small slits in the top crust to allow steam to escape.
2 cups blueberries
Bake the pie in the preheated oven for 45 minutes until the crust is golden brown and the filling is bubbling around the edges. Remove from oven and let cool for at least 2 hours before serving to allow the filling to set.
