CRUST:

1 1/2 c. all-purpose flour
1 1/4 c. quick-cooking oats
1 c. firmly packed brown sugar
1/2 c. melted butter

FILLING:

6 c. fresh or frozen blueberries, thawed and drained
1 c. sugar
1 c. water
3 tbsp. cornstarch
1/4 tsp. salt
1 tsp. vanilla

Heat oven to 350 degrees. In large mixing bowl, combine crust ingredients. Beat until crumbly, 1-2 minutes. Press 2 cups of mixture in the bottom of ungreased 9x13 inch baking pan. Place blueberries over crumb crust.

In 2-quart saucepan, combine filling ingredients except vanilla. Cook over medium heat, stirring occasionally, until mixture thickens and comes to a full boil, 18 to 22 minutes. Boil for 1 minute. Stir in vanilla. Pour over blueberries, sprinkle with remaining crumbs. Bake for 50 to 60 minutes and lightly browned. Top with whipped cream or ice cream. Makes about 12 servings.