Step 1

Preheat oven to 350*F

Step 2

Spray a 9x13 Casserole Dish

Step 3

In bottom of casserole dish combine rhubarb, strawberries and sugar. Mix well.

Step 4

Sprinkle jello evenly over rhubarb mixture.

Step 5

Sprinkle marshmallows over jello.

Step 6

In a separate bowl make cake mix according to package directions.

Step 7

Pour cake mix over marshmallows.

Step 8

Bake for 45 minutes. Watch after 30 to see if you need to tent cake with foil.

Step 9

Allow to cool for 5 minutes then flip cake upside down onto a large platter or cookie sheet. Slice and serve with ice cream or whipped cream.