01 - Whisk buttermilk, hot sauce, salt, pepper, garlic powder, and paprika in a bowl. Add chicken thighs, ensuring full coating. Marinate for at least 20 minutes, or overnight in refrigerator for optimal flavor penetration.
02 - Combine flour, cornstarch, salt, paprika, cayenne pepper, onion powder, and garlic powder in a large bowl. Mix thoroughly to distribute spices evenly.
03 - Remove chicken from marinade, allowing excess liquid to drip off. Press each piece firmly into the flour mixture, ensuring a thick, even coating. Transfer coated pieces to a wire rack.
04 - Pour vegetable oil into a deep skillet or Dutch oven to a depth of 1 inch. Heat oil to 350°F, maintaining consistent temperature throughout cooking.
05 - Fry chicken in batches for 5-7 minutes per side until golden brown and crispy. Verify doneness with an internal temperature of 165°F. Drain on wire rack or paper towels.
06 - Combine shredded cabbage, grated carrot, mayonnaise, apple cider vinegar, salt, and pepper in a bowl. Mix thoroughly until vegetables are evenly coated.
07 - Lightly toast burger buns if desired. Spread mayonnaise on bottom bun, layer with lettuce (if using), fried chicken thigh, slaw, and pickle slices. Top with remaining bun half.
08 - Serve immediately while chicken is hot and crispy for optimal texture and flavor.