Marinate the chicken: Place the chicken breasts or thighs in a bowl and pour in the buttermilk. Let them marinate for at least 30 minutes (or overnight in the fridge) to tenderize and add flavor.

1. Prepare the breading: In a shallow dish, combine the flour, garlic powder, onion powder, paprika, cayenne pepper (if using), salt, and pepper. In a separate dish, beat the egg.
2. Bread the chicken: Remove the chicken from the buttermilk, allowing excess to drip off. Dip each piece of chicken into the beaten egg, then coat it with the seasoned flour mixture, pressing gently to ensure the coating sticks.
3. Air fry the chicken: Preheat the air fryer to 375°F (190°C). Lightly spray the air fryer basket with olive oil. Place the breaded chicken in the basket in a single layer. Air fry for 10-12 minutes, flipping halfway through, until the chicken is golden brown and crispy and reaches an internal temperature of 165°F (74°C).
4. Make the hot honey sauce: While the chicken is cooking, combine the honey, hot sauce, apple cider vinegar, and chili flakes (if using) in a small saucepan. Heat over low heat, stirring occasionally, until the sauce is well combined and warmed through. Adjust the spice level by adding more hot sauce or chili flakes if desired.
5. Assemble the sandwich: Once the chicken is done, remove it from the air fryer. Toast the sandwich buns if desired. Drizzle the hot honey sauce generously over the crispy chicken. Add pickles, lettuce, tomato, or any other toppings of your choice. Place the chicken on the bottom bun, then top with the other half of the bun.
6. Serve: Serve the sandwich immediately, while the chicken is hot and crispy, and enjoy the delicious combo of sweet, spicy, and savory flavors!