This recipe is adapted from the original KFC Fried Chicken recipe published in the Chicago Tribune. Instead of 11 herbs and spices, it is simplified to fewer ingredients without sacrificing flavor.
Mix up the chicken with the salt and sugar. Let marinate at least 2 hours to overnight. This will impart extra flavor to the chicken, so each bite is juicy and flavored.
Whisk together all the flour ingredients in a large bowl. Coat each chicken piece with flour. Have a sheet pan lined with parchment paper or foil to put the coated chicken in.
Dip chicken pieces in buttermilk, then pack in the flour, and back to the lined sheet pan.
Let chicken rest for 30 minutes so the flour coating sticks to the chicken. You can put the chicken in the fridge or at room temperature.
Heat oil in a pan to 375 degrees. If you don't have a thermometer, it will start to look swirly. You want to catch the oil before it starts smoking. You can test the oil by dropping a bit of flour crumb into the oil to see if it starts bubbling. If it does nothing and sinks to the bottom, the oil is too cold.
Drop chicken pieces into hot oil in 1 layer. You may need to do this in 2-3 batches depending on how big your pan is. Fry for 4-5 minutes, flip with tongs, and fry until golden brown. It may look light golden, but you really want to leave the chicken inside the oil until it is a rich, dark golden brown.
Remove chicken from oil onto a rack or paper towels to drain excess oil. Let chicken cool for 5-10 minutes before the first bite to avoid burning your tongue.