If you are on Carnival, they make a desert called "Chocolate Melting Cake" which is made with bakers chocolate. But, on any cruise line, I would contact special services 2 weeks ahead of time to get exactly what you need.
Re. the photo's, I am like you in that I like unique scenic shots. But, I would never rent a vehicle or even hire a driver by myself. With my hubby, yes, but the only trouble I ever had on a cruise was deciding to hire someone on my own. If your GF doesn't want to go, try talking to your fellow passengers once you get on board. Sometimes you will find people who would love to do what you are thinking of, but were just too nervous to consider it. If not, then Chankanaab may give you more good shots than you expected.