This is a Gift Box cake my daughter, Ruth, and I made for her future sister-in-law's shower.
Under the layers of green fondant tissue paper is a white sheet cake with buttercream frosting - the bottom part of the box. Everything else is fondant.
For the box lid, I used a piece of styrofoam. I didn't think I would be able to support it if it was made of cake, but after doing it, I think it would have worked. So next time . . .
You also might notice the plastic in the bow. I found out two days before the party that the party was that week and not the next! Not enough time for a fondant bow to dry. So I improvised by cutting strips of plastic from a 2-liter plastic bottle to hold the bow up. It worked perfectly, except it showed up in the pics! It wasn't so noticeable at the shower.
Other than not enough of the fondant bra showing, I like the results.