01 - Whisk buttermilk, hot sauce, salt, pepper, garlic powder, and paprika in a bowl. Submerge chicken thighs completely and marinate for 20 minutes or overnight refrigerated.
02 - Combine flour, cornstarch, salt, paprika, cayenne, onion powder, and garlic powder in a large bowl, mixing thoroughly.
03 - Lift chicken from marinade, allowing excess to drip off. Press each piece firmly into flour mixture, coating completely and evenly. Transfer to wire rack.
04 - Pour vegetable oil 1 inch deep in heavy skillet or Dutch oven. Heat to 350°F.
05 - Cook chicken in batches, 5 to 7 minutes per side, until golden brown, crispy, and internal temperature reaches 165°F. Drain on wire rack.
06 - Toss cabbage, carrot, mayonnaise, vinegar, salt, and pepper together until evenly coated.
07 - Lightly toast buns if desired. Spread mayonnaise on bottom bun, layer lettuce, fried chicken, slaw, and pickles. Top with remaining bun half.
08 - Serve immediately while chicken remains hot and crispy.