SAUCE:

1 c. sugar
2 eggs
2 tbsp. cornstarch

Mix dry ingredients first and add eggs. Add:

1 c. water
1 tsp. vanilla

Cook until thick. Combine in bowl:

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

Add 1/2 cup butter. Place half of crumbs in 9x11 inch pan. Add 4 cups rhubarb. Top with sauce and then remaining crumb mixture. Bake at 350 degrees for 1 hour.