01 - Preheat the air fryer to 375°F for 3 minutes.
02 - In a small bowl, mix together the brown sugar and ground cinnamon until well combined.
03 - Lightly brush the pineapple slices with melted coconut oil or spray with cooking spray for extra caramelization, then sprinkle both sides with the sugar-cinnamon mixture.
04 - Arrange the seasoned pineapple slices in a single layer in the air fryer basket, working in batches if necessary to avoid overcrowding.
05 - Air fry for 8 to 10 minutes, turning the slices halfway through cooking, until the pineapple is lightly browned and caramelized.
06 - Drizzle with vanilla extract just before serving if using. Serve warm as is, or accompany with ice cream or yogurt.