1 c. flour
3/4 c. oatmeal
1/2 c. brown sugar
1/2 c. melted butter
4 c. diced rhubarb
1 c. sugar
1 c. water
1 tbsp. cornstarch
1 tsp. vanilla

Mix the first 4 ingredients together. Press half into a greased 9-inch baking pan. Cover with 4 cups diced rhubarb. Cook 1 cup sugar and 1 cup water thickened with 1 tablespoon cornstarch. Add 1 teaspoon vanilla. Pour over rhubarb, top with remaining crunch mixture. Bake 1 hour at 350 degrees.