Pat the turkey cutlets dry with paper towels to ensure a crisp exterior.
In a small mixing bowl, combine olive oil, minced rosemary, garlic, salt, pepper, and onion powder to create a marinade.
Coat both sides of the turkey cutlets thoroughly with the herb-oil mixture.
Preheat the air fryer to 375°F (190°C) for approximately 3 minutes.
Arrange the cutlets in a single layer in the air fryer basket, avoiding any overlap to ensure even air circulation.
Cook for 10 to 12 minutes, flipping the cutlets at the 6-minute mark.
Verify the internal temperature has reached 165°F (74°C) using an instant-read thermometer.
Remove from the air fryer and allow the meat to rest for 3 minutes before serving.