CRUST:

1/2 c. butter
1 c. flour
Pinch salt
2 tbsp. sugar
1 tbsp. white vinegar

FILLING:

1 c. sugar
1/4 tsp. cinnamon
2 tbsp. flour
4 c. fresh large blueberries

Combine crust ingredients and press into 9" springform bottom and 2" up the sides. Combine 1 cup sugar, 2 tablespoons flour, cinnamon and 2 1/2 cups blueberries and pour into crust. Bake at 400 degrees for 1 hour. Remove and put 1 1/2 cups remaining berries on top and cool. Refrigerate. Serve with vanilla ice cream or frozen yogurt. Serves 8.