01 - Peel the bananas and cut them into thin, even slices about 1/8 inch thick.
02 - In a small bowl, mix the sugar and cinnamon together until well combined.
03 - Brush the banana slices lightly with melted coconut oil on both sides, then sprinkle the cinnamon sugar mixture over both sides.
04 - Arrange the coated slices in a single layer in the air fryer basket. Work in batches if necessary to avoid overlapping.
05 - Air fry at 350°F for 10-15 minutes, flipping the chips halfway through. Watch closely during the last few minutes to prevent burning.
06 - Remove from the air fryer and let cool on a wire rack. The chips will crisp up as they cool. Sprinkle lightly with sea salt if desired.