Slice the chicken breast into even strips and submerge them in a bowl with the buttermilk to marinate for 30 minutes.
In a shallow dish, whisk together the whole wheat flour, garlic powder, onion powder, smoked paprika, sea salt, and black pepper.
Remove each chicken strip from the buttermilk, allowing the excess to drip off, then dredge thoroughly in the flour mixture until coated.
Preheat your air fryer to 375°F and lightly coat the basket with half of the avocado oil.
Place the chicken strips in a single layer in the basket and spray the tops with the remaining avocado oil to ensure a crisp finish.
Air-fry for 12 to 15 minutes, flipping the strips halfway through, until the coating is golden brown and the chicken is cooked through.
While the chicken cooks, whisk together the Dijon mustard, raw honey, and apple cider vinegar in a small bowl until smooth.
Serve the hot, crispy chicken strips immediately with the honey-mustard sauce on the side for dipping.