Combine buttermilk, maple syrup, egg, and 1 teaspoon granulated garlic in a resealable bag. Add chicken thighs and marinate for at least 1 hour or up to overnight in the refrigerator.
Combine flour, tapioca flour, salt, sweet paprika, smoked paprika, granulated onion, pepper, cayenne pepper, 1/2 teaspoon granulated garlic, and honey powder in a shallow bowl.
Preheat an air fryer to 380 degrees F (190 degrees C).
Drain and discard marinade from chicken thighs. Dredge chicken through flour mixture and shake off excess. Place chicken skin-side down in the preheated air fryer and cook for 12 minutes. Turn thighs and fry an additional 13 minutes.