Mash the banana: Peel the ripe banana and mash it in a bowl until mostly smooth. A few small lumps are fine. Measure out ½ cup mashed banana for the best texture.
Add the flour: Stir in ¾ cup self-rising flour until the mixture forms a soft, sticky dough. Stop mixing once the flour is fully blended in.
Check the texture: The dough should be sticky, moist, and able to hold a ball shape. If it’s too wet, add flour 1 tablespoon at a time. If it’s too dry, add a small spoonful of mashed banana.
Shape the donut holes: Lightly oil your hands, divide the dough into 7–8 pieces, and roll each piece into a small ball. Keep them close in size so they cook evenly.
Air fry: Spray the air fryer basket with oil. Place the dough balls in a single layer with space between them. Air fry at 350°F for 6–8 minutes, checking around 6 minutes.
Coat with cinnamon sugar: Mix cinnamon and sugar in a small bowl. Brush the warm donut holes with melted butter, coconut oil, or vegan butter, then roll them in the cinnamon sugar.
Serve warm: Enjoy right away while the centers are soft and the coating is sweet and warm. Serve with coffee, milk, tea, or yogurt if desired.
