I think it would be fairly easy to do this cake in buttercream, except the bow. I would crumb coat, then mark the crumbcoat with a straight edge to help keep track of where the icing color changes. I would ice the bottom color first, chill so that it is firm, then ice the top half. Then pipe on a border between the two colors. The ribbon would have to be fondant or gumpaste though.
I agree w/her ^^^