In a medium bowl, whisk together buttermilk, egg, and salt. Fully submerge chicken pieces in the bowl or place in a large ziplock bag and cover with the brine. Cover and refrigerate for 12–24 hours.
Preheat the oven to 175ºF (79ºC).
In a large dish, mix flour, cornstarch, and all 11 spices until well combined.
Drizzle a quarter cup of reserved brine into the dredge. Gently rub with your fingers to form lumpy bits, these create that signature craggy crunch.
Remove chicken from brine, letting excess drip. Press generously into the seasoned flour mix and coat thoroughly. Set the chicken aside on a cooling rack over a baking sheet to let the chicken rest and absorb some of the flour (this will help it stick better during deep frying)
Warm oil to 350°F (175°C) in a deep skillet or Dutch oven.
Fry chicken in batches. Dark meat for 8 minutes (or to 165°F internal), wings for 5 minutes, breasts for 6 minutes to 150°F internal. Avoid crowding and let oil recover between batches. It can take up to 5 minutes for it to recover.
Transfer to a wire rack for crispness and put it in the preheated oven.
Serve with coleslaw, biscuits, corn on the cob, or mashed potatoes and gravy for full comfort meal vibes.