Grease 6 muffin molds with cooking spray. Set aside.
In a large bowl, mix together the flour, sugar, baking soda, cinnamon and salt.
Add the banana and mix well.
Add the egg and mix well.
Add the oil and vanilla extract and mix until well combined.
Place the mixture into the prepared muffin molds.
Slide the Air Fryer Basket inside and adjust the temperature of Air Fryer to 320 °F to preheat for 5 minutes.
After preheating, arrange the muffin molds into the Air Fryer Basket in a single layer.
Slide the basket into Air Fryer and set the time for 12-15 minutes.
After cooking time is finished, remove the muffin molds from Air Fryer and place onto a wire rack to cool for about 10 minutes.
Carefully invert the muffins onto the wire rack to completely cool before serving.