Be sure to use bananas that are partially or mostly brown before peeling, which means they're ripe. Preheat the oven to 350 F and either line a 9x13 baking pan with parchment or grease the bottom and sides very well. In a large bowl, stir together the first 5 ingredients until evenly combined, then stir in remaining ingredients. Smooth into the pan, top with chocolate chips if desired. Bake on the center rack 30 minutes, then do not open the oven door even a little, but turn the oven off and let the pan sit in the turned-off oven for an additional 20 minutes. Garnish with additional peanut butter or maple syrup if desired, and serve hot or cold. This tastes even better if you loosely cover and refrigerate overnight, so I highly recommend serving it the day after it's made. Leftovers can also be sliced and frozen for up to two months.View Nutrition Facts