Preheat air fryer to 300°F (150°C).
In a bowl, mix the maple syrup, cinnamon, cayenne pepper, and vanilla extract until well combined.
Add the peanuts to the bowl and stir until they're evenly coated with the honey mixture.
Place the coated peanuts in the air fryer basket in a single layer. You might need to do this in batches, depending on your air fryer size.
Air fry for about 5-6 minutes, shaking the basket halfway through to ensure even roasting.
Keep an eye on them to prevent burning! They should be golden brown and smell spectacular when done.
Let them cool for a few minutes before enjoying your sweet and savoury treat!