Make cakes. Prepare batter following recipe directions. Bake and cool mini pumpkin and 2-layer round cake, 5 in. high. Place on foil-wrapped cake circle.
Cover cakes with fondant. Prepare buttercream icing following recipe directions. Use spatula to ice cakes smooth. Use white fondant to cover round cake and black fondant to cover pumpkin cake. Use knife to score lines on alternating pumpkin sections. Reserve remaining black fondant.
Make stripes. Use fondant roller with orange guide rings to roll out black fondant 1/8 in. thick. Use fondant trimmer to cut four strips, 3/4 in. wide x 18 in. long. Use damp brush to attach around sides of round cake, 5/8 in. apart.
Make stem. Roll a black fondant log, 1/4 in. wide x 1 in. dia. Use damp brush to attach to top of pumpkin.
Assemble cake. Position pumpkin cake on round cake. For bite marks, insert end of brush in round cake side. Squeeze red decorating gel into holes.