I used a scant 1/2 cup and a really firm banana. Kids devoured it.
A classic combination of flavors served quesadilla style. I enjoyed this very much; the only thing I would suggest is to cut back on the peanut butter a bit; I think it was just too much for one...
I never made any changes, I love simple and it was good. I made them ahead of time and then cooked them. My friends love peanut butter and they were happy with change.