My sister-in-law who is visiting made this just yesterday. Kids loved it. She found the recipe on youtube and added her own twist.
Rolled oats, chocolate chips, almonds, dates, ripe bananas, marshmallows. Just mix altogether, drop by spoonfuls on greased cookie sheet and bake for 7-8 minutes at 350 degrees. Flourless cookies, basically.
My guess is that you could pretty much add whatever you wanted to this! The oats and bananas are key though.