Prepare the Bananas:
Peel the bananas and slice them into thin rounds (about 1/8 inch thick). The thinner you slice them, the crispier they will be.

Mix Cinnamon-Sugar Coating:
In a small bowl, combine the sugar, cinnamon, and a pinch of salt (if using). Set this mixture aside.

Coat the Banana Slices:
Drizzle the olive oil or melted coconut oil over the banana slices and toss them gently to coat. Then, sprinkle the cinnamon-sugar mixture over the banana slices, tossing them to ensure even coverage.

Preheat the Air Fryer:
Preheat your air fryer to 350°F (175°C) for about 3-5 minutes.

Air Fry the Banana Chips:
Place the banana slices in a single layer in the air fryer basket. You may need to do this in batches depending on the size of your air fryer. Air fry the banana chips at 350°F (175°C) for 10-12 minutes, shaking the basket halfway through for even cooking.

Check for Crispiness:
Keep an eye on the chips towards the end of the cooking time to avoid overcooking. The banana chips will continue to crisp up a bit once they cool down.

Serve:
Once the banana chips are golden and crispy, remove them from the air fryer. Allow them to cool slightly before serving.