My Strawberry Upside-Down Cake

My Strawberry Upside-Down Cake 1 pint strawberries, cut up 1 6 oz. box of strawberry jello 3 cups of mini marshmallows 1 white cake mix, mixed as directed on the package Preheat oven to 350ºF. Spray 9X13 pan with cooking spray. Cut up strawberries and place in bottom of pan. Covering bottom evenly. Sprinkle dry gelatin over strawberries, then top with marshmallows. Mix cake mix as directed on box and spread over marshmallows. Bake for 40-50 minutes until toothpick comes out clean. Cool for about 15 minutes. Run a knife around edge of pan and invert cake onto serving dish (or in my case, a bigger pan, I didn't have a serving dish big enough). Serve warm or cold with a dollop of whipped cream.