2 1/2cupsblueberriesfresh or frozen (if using frozen, thaw and drain really well)
1 1/2tablespoonscold butter
Preheat oven to 400 degrees F. Prepare pie crust by covering the crust's edges with foil. This will help to keep the edges from getting too brown.
To make the filling, combine sugar and flour together in a medium sized mixing bowl. Using an electric mixer, beat in sour cream, egg, vanilla, and salt over medium speed for about five minutes. Carefully fold in the blueberries. Pour batter into pie crust and bake for 30 minutes.
While pie is baking, prepare the topping by crumbling together the flour, sugar, and butter with a fork.
Remove pie from the oven and sprinkle on the topping. Return to the oven and bake for 10-15 more minutes until topping is golden. Remove from oven and allow to cool throughly before slicing. Enjoy!