Spray a 9 by 13 inch pan with baking spray
Pour mini marshmallows evenly on the bottom of the pan
Prepare yellow cake mix according to box directions
Pour cake mix over marshmallows without mixing
Spread cake mix evenly over marshmallows
Sprinkle strawberry jello evenly over the cake mix, covering all corners
Place slightly thawed frozen sliced strawberries on top of the jello
Pour ⅔ cup of water over the top
Bake in a 350 degree oven for one hour
Cool and serve with Cool Whip
