CRUST:

1 c. flour
2 tbsp. sugar
Dash salt
1/2 c. (1 stick) unsalted butter
1 tbsp. white vinegar

Use a 9 inch tart pan with removable bottom. Preheat oven to 400 degrees. Prepare crust by mixing together flour, sugar and salt. Cut in butter until mixture is crumbly. Sprinkle with vinegar and gather dough together. press dough into bottom and sides of 9 inch ungreased pan.

FILLING:

4 c. blueberries (reserve 1 cup for top)
2/3 c. sugar
2 tbsp. flour
Dash cinnamon

Combine sugar, flour and cinnamon in large bowl. Toss with 3 cups blueberries. Fill shell with berries. Bake approximately 1 hour at 400 degrees. (Filling should be bubbling slightly). Remove tart from oven and immediately scatter remaining 1 cup (unsweetened) berries evenly on top. Let cool before serving.