Peel the plantain and cut it into uniform thickness slices between 1/8 inch to 1/4 inch thickness.
Spray basket bottom with avocado oil. Place slices in the basket and spray the tops lightly with oil.
Air fry at 350°F/175°C for 5 mins. Carefully take out, transfer to a cutting board, and smash the slices flat using a flat spatula or a drinking glass - anything flat will work.
Carefully return slices to the fryer basket in a single layer and air fry another 5 mins at 350°F/175°C.
Lightly spray with avocado spray again, then sprinkle with cinnamon and sugar, salt, or the seasoning of your choice.
Air fry at 200°F/100°C for up to 15 mins until they are all dried, checking them occasionally and removing them as they are done.
Allow to cool completely. Store in a sealed container on the counter for up to 10 days.
Notes
The plantain does not have to be super green, it can be semi-ripe.