01 - Whisk buttermilk, hot sauce, salt, pepper, garlic powder, and paprika in a bowl until thoroughly combined. Submerge chicken thighs completely in the mixture. Cover and refrigerate for at least 20 minutes, or overnight for optimal flavor penetration.
02 - Combine flour, cornstarch, salt, paprika, cayenne pepper, onion powder, and garlic powder in a large shallow bowl. Whisk together until spices are evenly distributed throughout the flour mixture.
03 - Remove chicken from marinade, allowing excess liquid to drip off. Dredge each thigh in the flour mixture, pressing firmly to adhere a thick, even coating. Shake off excess and place coated pieces on a wire rack.
04 - Pour vegetable oil to a depth of 1 inch in a deep skillet or Dutch oven. Heat oil to 350°F, maintaining temperature throughout frying process for optimal crispiness.
05 - Fry chicken in batches without overcrowding the pan. Cook for 5 to 7 minutes per side until golden brown and crispy, or until internal temperature reaches 165°F. Transfer to wire rack or paper towels to drain.
06 - Toss shredded cabbage and grated carrot in a bowl. Add mayonnaise, apple cider vinegar, salt, and pepper. Mix until vegetables are evenly coated. Adjust seasoning to taste.
07 - Lightly toast burger buns if desired. Spread mayonnaise on bottom buns, layer with lettuce, fried chicken thigh, coleslaw mixture, and pickle slices. Top with remaining bun halves and serve immediately.