Rhubarb Upside-Down Cake
["5 c. rhubarb, chopped", "1 c. sugar", "1 small box strawberry jello (sugar-free)", "1 cake mix (yellow or white)", "mini marshmallows"]
["Combine rhubarb, sugar and strawberry jello; set aside.", "In bottom of large cake pan (larger than 9 x 13-inch), cover bottom with marshmallows (not solidly).", "Mix cake according to package directions.", "Pour batter slowly over marshmallows.", "Drop rhubarb mixture by spoonful over cake batter evenly.", "Bake at 350\u00b0 for 40 minutes."]
["rhubarb", "sugar", "strawberry jello", "cake", "marshmallows"]