In a medium bowl, whisk together honey, Dijon mustard, garlic powder, onion powder, salt, and black pepper until well combined. Add the salmon pieces and gently toss to coat. Let marinate for 15-30 minutes in the refrigerator for enhanced flavor.
Set up a breading station: Place the flour in one shallow dish, the beaten eggs in another, and the panko breadcrumbs in a third dish.
Remove the salmon from the marinade, allowing excess to drip off. Dredge each piece in flour, shaking off the excess, then dip into the beaten eggs, and finally coat with panko breadcrumbs, pressing gently to adhere.
Preheat the air fryer to 400°F. Lightly spray the air fryer basket with cooking spray.
Arrange the breaded salmon nuggets in a single layer in the air fryer basket. Lightly spray the tops with cooking spray to promote crispiness.
Cook for 8-10 minutes, flipping halfway through, until the nuggets are golden brown and cooked through.
Serve warm with extra honey mustard sauce for dipping.