- Preheat your air fryer to 375°F (190°C) for a few minutes to ensure it's hot and ready for cooking. 
- Pat the chicken thighs dry with paper towels to remove any excess moisture. 
- In a small bowl, combine the salt, black pepper, garlic powder, and onion powder to create a seasoning blend. 
- Brush the olive oil evenly over the chicken thighs to help the seasoning adhere. 
- Sprinkle the seasoning blend over both sides of each chicken thigh, ensuring they are well coated. 
- Sprinkle the brown sugar evenly over the top side of each chicken thigh. The sugar will create a sweet glaze as it cooks. 
- Place the seasoned chicken thighs, skin-side up, in the preheated air fryer basket. Make sure they are not overcrowded to allow for proper air circulation. 
- Cook the chicken thighs at 375°F (190°C) for approximately 25-30 minutes. The exact cooking time may vary depending on the size of the thighs and your air fryer model. 
- Halfway through the cooking time, open the air fryer and carefully flip the chicken thighs to ensure even cooking and browning. 
- The chicken thighs are done when they reach an internal temperature of 165°F (74°C) and the skin is crispy and browned. Use a meat thermometer to check for doneness. 
- Once cooked, remove the chicken thighs from the air fryer and let them rest for a few minutes to allow the juices to redistribute. 
- Serve your Air Fryer Brown Sugar Chicken Thighs hot, garnished with fresh herbs or a drizzle of extra brown sugar glaze if desired.