Plug in your air fryer and preheat it to 350° Fahrenheit. ( This step is really important for the best results ).
While your air fryer is heating up, peel and slice your bananas. I like to slice them very thin. This makes them come out quite hard and very crispy
Spray the banana slices very lightly with a spritz of oil. This will help them to crisp up really well.
Season the slices with a spice of your choice.
Place the banana slices in the basket of the air fryer. It is important to arrange them in a single layer, with no overlapping. If they overlap they will stick together, and will not get crispy.
Cook for 6 minutes at 350°.
As soon as the timer goes off, pull out the basket and turn the slices over carefully, using a pair of silicone tongs.
Put them back into the air fryer, and cook for another 6 minutes.
Take them out, and remove the slices from the basket, using a silicone or wooden spoon. Spread them out on a baking tray to cool. They should be deliciously crispy once fully cooled.
When they are completely cold, store them in an airtight container.