In a medium bowl, combine all-purpose flour, garlic powder, ground black pepper, and sea salt. Whisk until well mixed.

Slice the fresh banana peppers in half lengthwise and remove the seeds.

Dip each banana pepper half into the seasoned flour mixture, coating thoroughly. Shake off excess flour and let sit for 5 minutes.

Preheat your air fryer to 350°F (175°C).

Arrange the coated banana pepper halves in a single layer in the air fryer basket. Lightly spray tops with olive oil.

Air fry the banana peppers for about 8 minutes, checking occasionally. Add 1-2 minutes for extra crispiness if needed.

Transfer cooked peppers to a paper towel-lined baking sheet and let cool for 5 minutes before serving.