01 - Whisk buttermilk and hot sauce in a bowl. Add chicken breasts, cover, and refrigerate for at least 30 minutes or up to 4 hours for enhanced flavor penetration.
02 - Combine flour, cornstarch, paprika, garlic powder, onion powder, cayenne pepper, salt, and black pepper in a separate bowl. Mix thoroughly until spices are evenly distributed.
03 - Remove chicken from marinade, allowing excess liquid to drip off. Press each piece firmly into the flour mixture, ensuring complete and even coating on all sides.
04 - Heat 1 inch of vegetable oil in a large skillet or deep fryer to 350°F. Fry chicken breasts for 4 to 5 minutes per side until golden brown and internal temperature reaches 165°F. Drain on paper towels.
05 - Combine mayonnaise, sour cream, Dijon mustard, honey, lemon juice, hot sauce, smoked paprika, salt, and pepper in a small bowl. Whisk until smooth and creamy. Refrigerate until assembly.
06 - Spread a generous layer of sauce on the bottom half of each toasted bun. Layer with shredded lettuce, fried chicken breast, tomato slices, and pickles. Place bun top and serve immediately.