Whisk the buttermilk, pickle juice, hot sauce, and kosher salt in a large bowl.
Add the chicken pieces to the marinade, ensuring full coverage, and refrigerate for 4-12 hours.
Whisk together the flour, cornstarch, and all seasonings in a large dish until well combined.
Remove each chicken piece from the marinade, letting excess drip off.
Dredge each piece thoroughly in the seasoned flour mixture, pressing firmly for an even coat.
Place the coated chicken on a wire rack and let rest at room temperature for 20-30 minutes.
Heat 3 inches of peanut oil in a Dutch oven to 325°F.
Add chicken pieces carefully, maintaining oil temperature around 300-310°F.
Fry for 15-20 minutes, turning occasionally, until deep golden brown and internal temperature reaches 165°F.
Transfer to a clean wire rack and sprinkle with extra salt.
Let rest for 5 minutes before serving.