Amazing artsistry W fondant these days, but before this, I made sheet cakes for the kids with “a filled, miniature wooden buried treasure chest” that I would 1st wrap W foil, & BURY IN THE BATTER BEFORE BAKING. “X” would mark the spot. The chest & contents of mini coins + even mini-plastic “pearls” did well in the baking. The kids were crazy about it. Also, a treasure hunt @ the party is a must.