Marinate the chicken
In a large bowl, toss the Chicken with the Buttermilk, Kosher Salt, and Hot Sauce until every piece is well coated. Cover and refrigerate for 30 minutes so the chicken picks up flavor and the coating later sticks better.
Mix the dredge
While the chicken marinates, whisk together the All-purpose Flour, Cornstarch, the remaining salt, Paprika, Garlic Powder, Onion Powder, Pepper (Black) (freshly ground), Cayenne Pepper, and Baking Powder in a wide, shallow dish. Keep whisking until the spices are evenly speckled through the flour and there are no clumps.
Dredge the chicken
Lift each piece out of the marinade, let the excess drip off, and press it firmly into the flour mixture until every surface is coated. Shake off the loose flour, set the pieces on a plate or tray in a single layer, and let them sit for 10 minutes so the crust hydrates and clings better. Discard the used marinade.
Heat the oil
While the coated chicken rests, pour the Peanut Oil into a heavy pot until it comes about 2 inches deep, then heat it over medium-high until a thermometer reads 350° F. Keep the temperature steady so the first batch fries evenly instead of soaking up oil.
Fry the chicken
Working in batches of 4 or 5 pieces, carefully lower the chicken into the hot oil. Fry for 8 minutes, turn the pieces, then fry for 6 to 8 minutes more, letting the oil return to 350° F before each new batch. The chicken is ready when the crust is deep golden brown and the thickest piece reaches 165° F without touching bone.
Drain and serve
Transfer the chicken to a paper towel-lined plate or tray and let it drain for 5 minutes. Serve it hot while the crust is still shatteringly crisp.
