Rhubarb Crunch

Something from my childhood! So I haven't actually made this yet, but I have eaten it, and it is fabulous.

Ingredients:

4 Cups diced rhubarb
1 Cup sugar
2 Tablespoons cornstarch
1 Cup flour

3/4 Cup oatmeal

1 Cup brown sugar

1/2 Cup melted butter

1 Cup water

1 Teaspoon cinnamon

1 Teaspoon vanilla

Directions:

Mix flour, oatmeal, brown sugar, butter, cinnamon. Crush mixture into a greased 9" square pan - saving 1/3 for topping. Cover with rhubarb. Combine rest of ingredients in saucepan and cook until thickened, stirring constantly. Pour sauce over rhubarb and cover with topping. Bake 350* for 1 hour. Cut into squares and serve warm with whipped cream or ice cream.