Stack two sheet cakes for bottom of grill with icing in between. In the center of the top cake, carve out the pit area of the grill. Ice cake with crumb coat. Line pit with gray fondant. Cut large marshmallows in half and spray paint with black icing paint and place in the pit area. Cover large pretzels with black fondant and lay across the pit for the grill grates. Form fondant for bottom of the slab of ribs and break kit kat candy bars in half and lay on bottom fondant. Form top of slab of ribs from fondant and place over candy bars working a small space between each candy bar. Used white butter mints painted a bone color for the little bones on the ribs. Shape corn and hot dog from colored fondant and place on the grill top.