In a large bowl, sift together flour, sugar, brown sugar, baking powder, salt and cinnamon; combine.
In another mixing vessel combine mashed bananas, milk, peanut butter, egg, oil, and vanilla; mix well.
Add this to the dry mixture previously prepared; mix just enough to combine.
Stir in chocolate chips.
Spray muffin tins with cooking spray, if you are using liners, spray those too, and fill tins ¾ full.
Preheat oven to 350 degrees and bake for 20-25 minutes or until a toothpick comes out clean.
