This is a white cake with buttercream frosting. The characters and wording were done by piping melted chocolate (I've been hooked on this technique since getting The Whimsical Bakehouse cookbook . . . I love it!)
The cake did not end up tasting as I had hoped . . . but I learned my lesson that I always need to test each recipe before making it for someone else. You'd think I would have known that ! Oh well . . . live and learn.