Rhubarb Upside-Down Cake
["4 c. diced rhubarb", "1 1/2 c. sugar", "2 c. miniature marshmallows", "1 (3 oz.) box strawberry jello", "1 yellow or white cake mix"]
["Mix and put in bottom of 9 x 13-inch baking pan.", "Mix white or yellow cake mix according to directions on box.", "Pour over mixture and bake until cake tests done.", "Let cool to lukewarm before turning out.", "Bake at oven setting on cake mix box."]
["rhubarb", "sugar", "marshmallows", "strawberry jello", "white cake"]