Preheat oven to 350 degrees. Prepare a 9” baking pan (round or square) with parchment paper, or use a silicone pan.
In the work bowl of a food processor fitted with the S blade add the cooled roasted Japanese sweet potatoes, garbanzo beans, aquafaba, dates, banana, cocoa, cinnamon, vanilla extract, baking powder, baking soda, and cherries. Process until smooth. Add the rolled oats and process using the pulse function until they are well incorporated. Add cacao nibs and/or unsweetened chocolate chips if desired. They can go in the batter or just on top. (They are not necessary; the brownies are delicious without them.)
Spread batter evenly in prepared pan. Bake for 25 minutes or until done. Don’t overbake as we want them to be fudgy. Enjoy warm or cold.