01 - In a large bowl, combine the buttermilk and hot sauce. Add the chicken pieces, turning to coat thoroughly. Cover and marinate in the refrigerator for at least 1 hour, or overnight for best results and maximum flavor penetration.
02 - Preheat oven to 425°F. In a large bowl, whisk together flour, baking powder, baking soda, salt, and sugar until well combined. Add cold butter cubes and use a pastry cutter or your fingers to work it in until the mixture resembles coarse crumbs with some pea-sized butter pieces remaining. Stir in cold buttermilk just until combined; do not overmix.
03 - Turn dough onto a lightly floured surface and gently pat into a 1-inch thick rectangle. Use a round cutter to cut biscuits, pressing straight down without twisting. Reroll scraps only once if needed. Place biscuits on a parchment-lined baking sheet. Brush tops with extra buttermilk. Bake for 12–15 minutes until golden brown on top. Cool slightly before serving.
04 - In a shallow dish, whisk together flour, cornstarch, paprika, garlic powder, onion powder, cayenne pepper, salt, and black pepper. Remove chicken from marinade, allowing excess liquid to drip off. Dredge each piece thoroughly in the seasoned flour mixture, pressing firmly to adhere the coating. Place dredged chicken on a wire rack and let rest for 10 minutes to help the coating set.
05 - Fill a large, heavy skillet or Dutch oven with 1 inch of vegetable oil. Heat to 350°F, monitoring with a thermometer. Fry chicken in batches without overcrowding, placing pieces skin side down first. Cook until golden brown and cooked through to an internal temperature of 165°F, approximately 15–18 minutes per batch. Transfer to a wire rack or paper towels to drain.
06 - Serve the hot fried chicken alongside freshly baked buttermilk biscuits. Offer honey, hot sauce, or gravy on the side for dipping. Serve immediately while chicken is crispy and biscuits are warm.