1 c. flour
3/4 c. oatmeal
1 c. brown sugar
1/2 c. butter
1 tsp. cinnamon

Mix above ingredients until crumbly. Put half mixture in 9"x12" pan. Cover with 4 cups diced rhubarb. Cook 2 tablespoons cornstarch, 1 cup water and 1 teaspoon vanilla until thick and clear, stirring constantly. Pour over rhubarb, add mixture on top. Bake until brown at 350 degrees. Serve with whipped cream or ice cream.