Add diced sweet potatoes to a large bowl, then drizzle the olive oil overtop and stir. Then, add the chili powder, salt and pepper and stir until the potatoes are coated.
Spray your air fryer with avocado oil (or olive oil or nonstick) spray, then add the sweet potatoes, making sure they're not overlapping too much.
Air fry the potatoes at 400° for 12-16 minutes, stopping half way through to shake the basket. NOTE: cook time varies depending on the size of your sweet potatoes. Enjoy!