That typical graham cracker flavor comes from a combination of graham flour and honey. I don't usually have graham flour on hand, but I found some at a nearby bulk food store without too much trouble. It's similar in appearance to regular whole wheat flour, but with larger pieces of bran.
I'm happy to report that they taste just like graham crackers (who'd a thunk?!)! Most of them were gobbled up within the first day, but we've got a few left almost a week later and they still taste good. The true test will be whether I can use them for pie crusts (or s'mores!).