Heat oven to 425° F.
Mix flour and salt in a large bowl. Whisk milk, egg, and hot sauce in another bowl.
Put butter into a 13x9x2-inch baking dish; place it in the oven for 5 minutes or until the butter melts. Remove from the oven.
Working with one piece at a time, dredge the chicken in the flour and shake off excess; dip into milk mixture, letting excess drip off. Dredge again in the flour. Arrange chicken, skin side down, in a single layer, in the baking dish.
Bake for 30 minutes; turn chicken so that the skin side is up. Bake 15 minutes longer or until a thermometer inserted into the thickest part of the chicken reads 165° F.
Combine the oil, cayenne pepper, brown sugar, chili powder, garlic powder, and paprika in a small saucepan; cook over medium heat until warm. Brush fried chicken with spicy oil.
Serve chicken with Honey Pecan Slaw and baking powder biscuits, if desired.