01 - Whisk buttermilk with salt, garlic powder, onion powder, cayenne pepper, and black pepper in a large bowl until fully incorporated. Submerge chicken pieces in marinade, ensuring complete coverage. Cover bowl and refrigerate for minimum 2 hours, preferably overnight for optimal 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 buttermilk marinade, allowing excess liquid to drip off. Press each piece firmly into flour mixture, ensuring thick, even coating on all sides. Arrange coated chicken 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 in small batches, avoiding overcrowding. Fry for 12 to 15 minutes, turning pieces occasionally, until exterior is golden brown and crisp and internal temperature reaches 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.