01 - Whisk buttermilk with salt, garlic powder, onion powder, cayenne pepper, and black pepper in a large bowl until fully combined. Add chicken pieces, turning to coat completely. Cover bowl and refrigerate for minimum 2 hours, ideally overnight for maximum flavor penetration.
02 - Combine flour, paprika, salt, black pepper, cayenne pepper, and baking powder in a separate bowl. Whisk thoroughly to distribute spices evenly throughout the flour mixture.
03 - Remove chicken from marinade, allowing excess liquid to drip off. Dredge each piece in flour mixture, pressing firmly to ensure thick, even coating adheres to all surfaces. Arrange coated pieces on wire rack and rest for 10 minutes to set coating.
04 - Pour vegetable oil into deep fryer or heavy-bottomed pot. Heat to 350°F, monitoring temperature with kitchen thermometer for accuracy.
05 - Carefully lower chicken pieces into hot oil, working in batches to avoid overcrowding. Fry for 12-15 minutes, turning pieces occasionally for even browning. Cook until golden brown and crispy with internal temperature reaching 165°F.
06 - Transfer fried chicken to wire rack or paper towels to drain excess oil. Let rest for 5 minutes before serving to allow juices to redistribute and coating to set.