01 - Whisk buttermilk with salt, garlic powder, onion powder, cayenne, and black pepper in a large bowl until fully combined. Submerge chicken pieces ensuring complete coating. Cover bowl and refrigerate minimum 2 hours, preferably overnight for optimal flavor penetration.
02 - Combine flour, paprika, salt, black pepper, cayenne, 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. Press each piece firmly into flour mixture, turning to coat all surfaces. Place coated pieces on wire rack and rest for 10 minutes to help coating adhere.
04 - Pour vegetable oil into deep fryer or heavy pot to sufficient depth for submerging chicken. Heat oil to 350°F using kitchen thermometer for accurate temperature control.
05 - Carefully lower chicken pieces into hot oil working in batches to prevent overcrowding. Fry 12-15 minutes, turning occasionally, until golden brown and crisp with internal temperature reaching 165°F.
06 - Transfer fried chicken to wire rack or paper towels to drain excess oil. Let rest 5 minutes before serving to allow juices to redistribute and coating to set.