Cut chicken breast into 3/4-inch pieces.
Sprinkle with 1/2 teaspoon salt, dust with flour, and toss to coat.
Combine breadcrumbs, garlic powder, smoked paprika, and 1/2 teaspoon salt in a bowl.
Drizzle with cooking oil and stir until mixture resembles damp sand.
Pour buttermilk into a small bowl.
Line up seasoned chicken, buttermilk, and breadcrumbs.
Dip chicken pieces in buttermilk, then coat with breadcrumbs.
Press gently to adhere and set aside.
Preheat air fryer to 400°F.
Arrange nuggets in a single layer in the basket.
Air-fry for 8 minutes, flipping halfway, until golden and crispy.
Remove nuggets and let rest for 3–5 minutes.
Serve warm with your favorite dipping sauce.