Take out a large mixing bowl and mash your banana until it's smooth with no large lumps.
Add all of your wet ingredients and mix everything together.
Add your dry ingredients into the bowl with the wet ingredients and mix until a thick dough forms. Fold in any optional add-ins at this stage. Cover the bowl and refrigerate the dough for 30 minutes.
Preheat your air fryer to 350°F. Line the basket with parchment paper.
Using a medium cookie scoop, portion the dough and roll it between your palms into smooth balls. Lightly oil your hands if the dough is sticky. Place the balls in the air fryer basket with space between each one. Cook at 350°F for 8 to 10 minutes.
Let them cool for 5 minutes before eating — they firm up significantly as they cool.