PIE:

1 c. sour cream
3/4 c. sugar
2 tbsp. flour
1/4 tsp. salt
1 tsp. vanilla
1 egg
2 c. diced tart apples
8 inch unbaked pie shell

TOPPING:

1/2 c. brown sugar
1/3 c. flour
1/4 c. butter

Preheat oven to 375 degrees. Peel and dice apples. Pour sour cream, sugar, flour, salt, vanilla and egg in large bowl and beat together. Add apples and mix until apples are coated. Pour mixture into unbaked pie shell. Bake for 25 minutes. While pie is baking, mix together brown sugar, flour and softened butter. Sprinkle mixture over top of pie, return to oven and bake 20 minutes longer.