01 - In a large bowl, combine buttermilk and hot sauce. Add chicken pieces and turn to coat. Cover and refrigerate for at least 1 hour (up to overnight).
02 - Preheat oven to 450°F. In a large bowl, whisk together flour, baking powder, baking soda, salt, and sugar. Cut in cold butter until mixture resembles coarse crumbs. Stir in buttermilk just until dough comes together.
03 - Turn dough onto a floured surface, gently pat to 1-inch thickness. Cut out biscuits using a 2.5-inch cutter. Place on a parchment-lined baking sheet. Bake for 12–15 minutes until golden. Cool slightly.
04 - In a shallow dish, mix flour, salt, pepper, paprika, garlic powder, onion powder, and cayenne. Remove chicken from marinade, letting excess drip off. Dredge in flour mixture, pressing to adhere.
05 - In a large, deep skillet or Dutch oven, heat 1 inch of oil to 350°F. Fry chicken in batches, turning occasionally, until golden brown and cooked through (internal temp 165°F), about 12–15 minutes. Drain on a wire rack.
06 - In a saucepan, melt butter over medium heat. Whisk in flour and cook 1–2 minutes. Gradually whisk in milk until smooth. Cook, stirring, until thickened, 4–5 minutes. Season with salt, pepper, and garlic powder.
07 - Arrange fried chicken and biscuits on plates. Spoon gravy over biscuits and serve immediately.