01 - Combine buttermilk and hot sauce in a large bowl. Add chicken pieces, coating thoroughly. Cover and refrigerate for at least 1 hour, preferably overnight.
02 - Preheat oven to 425°F. Whisk flour, baking powder, baking soda, salt, and sugar in a large bowl. Cut in cold butter using a pastry cutter until mixture resembles coarse crumbs. Stir in buttermilk just until combined; avoid overmixing.
03 - Turn dough onto floured surface and pat to 1-inch thickness. Cut with round cutter, rerolling scraps if necessary. Place on parchment-lined baking sheet, brush tops with buttermilk. Bake 12-15 minutes until golden brown.
04 - Mix flour, cornstarch, paprika, garlic powder, onion powder, cayenne, salt, and pepper in shallow dish. Remove chicken from marinade, shake off excess. Press each piece into seasoned flour to coat thoroughly. Rest on wire rack for 10 minutes.
05 - Heat 1 inch vegetable oil in heavy skillet or Dutch oven to 350°F. Fry chicken in batches, skin side down first, until golden brown and internal temperature reaches 165°F, about 15-18 minutes per batch. Drain on paper towels.
06 - Plate hot fried chicken alongside freshly baked biscuits. Serve with honey, hot sauce, or gravy if desired.