- Mix sugar and flour together in bowl.
- Beat in sour cream, egg,vanilla and salt together until smooth (about 5 minutes).
- Fold in blueberries.
- Pour into pie crust, and bake at 400F for 25 minutes.
- (May need to adjust temperature and time for frozen berries).
- Meanwhile, combine topping ingredients.
- Remove pie from oven after the 25 minutes, and sprinkle on topping.
- Return pie to oven and bake 10 minutes more.
- Chill before serving.