Find or make your own cardboard box, slightly larger than the size of your cake pan. The edges need to be slightly higher (about 1 to 2-inches) than the edge of the pan. Cover the box in aluminum foil, brown paper bags, or similar material.

Prepare and bake cake according to package directions using a 9x13-inch baking pan. Allow to cool completely.

While the cake is cooling, lay out a square of waxed paper. Melt candy melts according to package directions. Dip pretzel sticks into the candy melts and lay on the wax paper to form a goal post shape. You may need to use an extra dab of melted candy melts in the corners to ensure they stay together.

Tint one can of frosting to the desired shade of green using green food coloring. Evenly spread the frosting over the top of the cake.

Place half of the can of white frosting into a ziptop bag and seal. Save remaining frosting for another use. Snip a small piece off of the corner. Pipe a football field design onto the top of the cake. Leave room for an end zone at each end.

Unwrap 10 SNICKERS Minis bars and arrange on the football field as the players. Using the white frosting in the ziptop bag, pipe "x" on one team and "o" on the other team.

Place the cake pan centered inside your prepared cardboard box. Fill the seating area with Skittles and wrapped Snickers Minis.

Insert the goalposts into each end zone just before serving.