Preheat oven to 450 degrees.
Place pie crust in a 9” pie pan and prick the dough several times with a fork.
Bake 9-10 minutes.
In a large bowl, whisk sugar, flour, sour cream, eggs and vanilla.
Gently fold in the blueberries.
Pour into crust.
Making the Topping:
In a medium bowl, combine the melted butter, brown sugar, flour and oats.
Bake 55-60 minutes or until a toothpick inserted into the center comes out clean.
Cool completely before slicing.