Prep the chicken: Pat the chicken dry with paper towels. Cut into even, bite-sized pieces—about 1 to 1.5 inches—so they cook at the same rate.
Season: In a large bowl, toss chicken with olive oil, salt, pepper, garlic powder, onion powder, smoked paprika, and chili powder if using.
Sprinkle in the cornstarch and toss again until the pieces are lightly coated.
Preheat the air fryer: Set to 400°F (200°C) for 3 to 5 minutes. Lightly spray the basket if sticking is a concern.
Arrange in a single layer: Place the chicken bites in the basket without crowding. Work in batches if needed to keep airflow strong.
Air fry: Cook for 7 to 9 minutes, shaking the basket or flipping once halfway through.
The bites are done when the edges are browned and the internal temperature hits 165°F (74°C).
Rest briefly: Let the bites sit for 2 minutes to lock in juices.
Finish and serve: Squeeze on fresh lemon, sprinkle parsley, or drizzle hot honey for a sweet-heat finish. Serve with your favorite dip or over a salad, rice, or roasted veggies.