Lauren at The Burlap Bag), the recipe couldn't be simpler:
2 large ripe bananas, mashed
1 cup quick-cooking oats
Mix together, drop onto greased or parchment-lined cookie sheet, bake at 350 in a preheated oven for 15 minutes.
I added in 1 tsp. cinnamon and a handful of dried cranberries, and I HIGHLY recommend adding some of your own favorites, because the cookie is a little one-note (of bananas) without them. Chocolate chips, flax seed, peanut butter - I have seen recipes that added all of those in with excellent results.
Try them and let us know what you think!