This is wonderful cake, but can be pretty pricey if you don't have a "source" for the rhubarb (usually a gardener in a fairly cool climate). But it will probably be a lovely cake with other fruit, though most other fruit may need less sugar.
Prepare one boxed yellow or white cake mix as directed Pour into greased 9x13 baking pan Sprinkle 5 cups rhubarb over the batter Sprinkle 1 cup of sugar over the rhubarb Pout 1 cup of heavy cream over the top Bake according to cake directions, but be prepared to add additional time as needed (usually about 45 minutes) Refrigerate after cooled.