This was my son's 5th birthday cake. The football was chocolate chocolate chip cake with marshmallow filling and chocolate buttercream, and the field was french vanilla cake with vanilla buttercream. I'm still looking for a good chocolate buttercream recipe for decorating. I can't seem to get it right. The football wasn't perfect, but I was pretty happy with the way the field turned out. Still, my son loved it, and the people at the party loved how it tasted, so we'll call it a success. It was good practice - I need to do more tiered cakes. Thanks to Alongino for inspiration for the field.