In a bowl, mash the ripe banana. Add the flour and mix with a spatula or fork.

Once the dough becomes crumbly, begin using your hands to create a smooth (but sticky on the inside) dough. Mix just until a ball forms. (Do not overmix.)

Divide the dough into 7 equal pieces. Lightly oil your hands and roll each piece of dough into a ball.

Spray the basket of an air fryer with non-stick cooking spray. Arrange the donut holes in the basket, making sure they are not touching each other.

Cook in a 350F (177C) air fryer for 6 minutes.

Carefully remove the donuts from the air fryer. Lightly brush with the remaining oil and then roll in cinnamon sugar.

Enjoy warm!