Marinate the Chicken: In a deep bowl, combine the buttermilk, salt, black pepper, and optional Buffalo hot sauce to create a flavorful marinade that makes the chicken tender and juicy. Submerge the chicken pieces in the marinade so they are completely covered, then cover the bowl and refrigerate for 3–4 hours to maximize flavor and tenderness; if short on time, marinate for at least 30 minutes.

Prepare the Breading: In a separate bowl, mix together the flour, cornstarch, paprika, garlic powder, onion powder, cayenne pepper, salt, and any optional dried herbs like thyme or oregano to create the breading mixture. Stir thoroughly to ensure the spices are evenly distributed throughout the mixture, which will add delicious aroma and extra crispiness to the chicken.

Bread the Chicken: After marinating, remove the chicken pieces from the marinade, allowing any excess liquid to drip off so the breading adheres better. Coat each piece of chicken in the breading mixture, pressing down to create a thick, even layer; for an even crispier crust, dip the chicken back into the marinade and then re-coat in the breading mixture.

Air Fry the Chicken: To ensure a crispy coating when air frying, lightly spray or brush each piece of chicken with oil. Arrange the chicken pieces in the air fryer basket, leaving space between them for even cooking. Cook at 375°F (190°C) for about 15–18 minutes, flipping halfway through and spraying with more oil; before serving, check that the internal temperature of the chicken has reached 165°F (75°C) to ensure it’s fully cooked.

Make the Sauce: In a small bowl, combine mayonnaise, Greek yogurt, garlic powder, soy sauce, and lemon juice until smooth to create a creamy and slightly tangy sauce that complements the spicy chicken. Taste and adjust with more salt or lemon juice if desired to achieve your preferred flavor.

Toast the Buns: Slice the buns in half and toast the cut sides on a skillet or in the air fryer for 1–2 minutes until golden. This toasting helps the buns hold the filling and prevents them from getting soggy when served with the chicken.

Assemble the Burger: Spread a layer of sauce on the bottom half of the bun. Add a layer of lettuce for crunch, then place the crispy chicken on top of the lettuce. Add a slice of tomato for freshness and drizzle a bit more sauce on top of the tomato for extra juiciness. Finally, cover with the top bun to complete your burger.