Made this for my son's 7th birthday. The bottom cake is a two chocolate butter cakes filled with italian meringue butter cream frosting, covered with black fondant to make it look like a tire. The top cake is a yellow butter cake with the same frosting. Created the ramp out of rice kripsy treats and topped it off with crushed oreos and graham crackers to look like gravel. Lined the top cake with oreos decorated to look like monster truck wheels.