Pat the pork dry: Use paper towels to remove surface moisture. This helps the rub stick and promotes browning.
Trim if needed: Leave a thin fat cap for flavor, but remove thick, hard fat or silver skin so the seasoning can penetrate.
Season generously: In a small bowl, mix salt, pepper, garlic powder, onion powder, paprika, and thyme. Rub olive oil over the pork, then coat all sides with the seasoning blend.
If using brown sugar or honey, add it now for a light glaze.
Preheat the air fryer: Set to 360°F (182°C) for 3–5 minutes. A hot basket helps sear the outside.
Arrange in the basket: Place the pork loin in the air fryer basket, fat side up, allowing space around it for airflow.
Cook: Air fry at 360°F (182°C) for 25–35 minutes, depending on thickness. Flip halfway if your air fryer browns unevenly.
Begin checking temperature at the 22-minute mark.
Check doneness: Insert an instant-read thermometer into the center. You want 145°F (63°C). The temperature will rise slightly during resting.
Rest: Transfer to a cutting board and tent loosely with foil.
Rest for 8–10 minutes to let juices redistribute.
Slice and serve: Cut into 1/2-inch slices against the grain. Spoon any juices over the top and finish with a squeeze of lemon or sprinkle of parsley if you like.