Place the chicken breast in a shallow bowl and pour the buttermilk over it, ensuring it is fully coated. Let it marinate for at least 10 minutes.
In a separate shallow dish, whisk together the oat flour, almond flour, garlic powder, onion powder, smoked paprika, sea salt, and black pepper.
Preheat your air fryer to 390°F (200°C).
Remove the chicken from the buttermilk, letting any excess drip off, then dredge it thoroughly in the flour and spice mixture, pressing to adhere.
Lightly spray the air fryer basket with avocado oil. Place the chicken in the basket and spray the top of the chicken with a quick mist of avocado oil.
Air fry for 12-15 minutes, flipping halfway through, until the internal temperature reaches 165°F and the crust is golden brown.
While the chicken is finishing, toast the whole grain waffle until crisp.
Place the toasted waffle on a plate, top with the crispy chicken breast, and drizzle with the maple syrup before serving.