Mix the buttermilk, hot sauce, salt, black pepper, cayenne, and garlic powder in a large bowl. Put the chicken pieces in the buttermilk mixture and coat completely.

Marinate at least 8 hours and up to 24 in the refrigerator.

Remove the chicken from the refrigerator. In a large paper or plastic (sturdy) bag, mix flour with black pepper, cayenne, salt, and garlic powder.

A couple pieces at a time, add the chicken to the seasoned flour and shake until thoroughly coated. Shake off any excess flour and let the dredged chicken pieces sit on a platter at room temperature for 20 to 30 minutes.

Meanwhile, heat 1/2 inch of oil in a large, heavy-bottomed skillet on medium heat (cast iron, stainless steel, or anodized aluminum—something that can take the heat). Heat until a pinch of flour gently sizzles when dropped in the hot oil (but not so hot that the pan is smoking), about 325°F. Remember when working with hot oil, always have a pan lid close by, just in case of grease fire.

Working in batches, add the chicken pieces to the hot oil in the pan and fry until golden brown all over, about 8 to 10 minutes per side, flipping the chicken as needed with tongs. When done, the meat should register 165°F in the thickest part using a digital thermometer.

Use tongs to remove chicken from pan. Place on a rack over a cookie sheet or a platter layered with paper towels for the excess oil to drain. Serve warm.