In a medium sized bowl mash the banana well with a fork.
Add flour, baking powder and salt. Stir the dry ingredients into the banana with a spatula. Dough will not be perfectly smooth but a little shaggy looking. Knead the dough and form into a ball with fingers sprayed with olive oil or avocado oil spray. Dough will somewhat be sticky.
Scoop dough into balls with a cookie scoops. Place the balls of dough on an air fryer pan lined with parchment paper leaving space between the dough balls. You should have 8 balls of dough.
Spray or brush olive or avocado oil on the top of the balls of dough.
Cook in air fryer at 350 degrees for 6-7 minutes or until the donut holes are golden brown. Cook in batches if needed depending on the size of your air fryer.
In the meantime, mix the sugar, cinnamon and nutmeg (optional) together in a small bowl you can dip the donut holes into.
When the donut holes are done, spray or brush them with a little olive oil or avocado oil and dip into the sugar cinnamon mixture. Do this one at a time so the oil doesn't absorb into the donut holes.
Makes 8 donut holes. Serving size based on 2 donut holes.