01 - Whisk buttermilk, hot sauce, salt, pepper, garlic powder, and paprika in a bowl. Add chicken thighs, ensuring full coating. Marinate at least 20 minutes (up to overnight refrigerated for optimal results).
02 - Combine flour, cornflour, salt, paprika, cayenne, onion powder, and garlic powder in a large bowl, mixing thoroughly.
03 - Remove chicken from marinade, allowing excess to drip off. Press each piece into flour mixture, ensuring thick, even coating. Place on wire rack.
04 - Pour 1 inch vegetable oil into deep skillet or Dutch oven. Heat to 350°F.
05 - Fry chicken in batches 5-7 minutes per side until golden, crisp, and cooked through (internal temperature reaches 165°F). Drain on wire rack or paper towels.
06 - Combine cabbage, carrot, mayonnaise, vinegar, salt, and pepper in a bowl. Mix until well incorporated.
07 - Toast buns lightly if desired. Spread mayonnaise on bottom bun, add lettuce (optional), fried chicken thigh, slaw, pickle slices, and top bun.
08 - Serve immediately while hot and crispy.