Yellow Cake for decorating - something that will stand up to cutting but still taste great

I am making a Wallace and Gromit cake for my son's 3rd birthday, and he has asked (gasp!) for a yellow cake. I don't know from yellow cake, as I'm a chocolate person. So, I need a tasty yellow cake recipe that is hardy enough to allow me to cut it out in the right shape and frost it (i.e. not so cumb-y that frosting the cut sides will make a mess). I'm thinking a dense, buttery cake will hold up best. Any suggestions?