01 - Peel the bananas and cut them into thin, even slices about 1/8 inch thick. A mandoline slicer works best for uniform thickness.
02 - Combine granulated sugar and ground cinnamon in a small bowl until evenly blended.
03 - Brush banana slices lightly with melted coconut oil on both sides, then sprinkle cinnamon sugar mixture evenly over both sides.
04 - Place coated banana slices in a single layer in the air fryer basket. Work in batches if necessary to prevent overlapping.
05 - Cook at 350°F for 10-15 minutes, flipping halfway through. Monitor closely during final minutes to prevent burning.
06 - Transfer chips to a wire rack and let cool completely. Chips will crisp further as they cool. Add sea salt if desired.