In a large mixing bowl, whisk together the buttermilk, dill pickle juice, hot sauce (if using), and 1 teaspoon of kosher salt to prepare the brine.
Add the chicken pieces to the brine, ensuring they are fully submerged. Cover and refrigerate for at least 4 hours or overnight.
In another bowl, combine the all-purpose flour, garlic powder, onion powder, paprika, remaining 2 teaspoons kosher salt, and black pepper. Mix well.
Heat cooking oil in a deep frying pot or large skillet to 350°F (175°C), enough to submerge chicken pieces halfway.
Remove chicken from brine, letting excess drip off. Dredge each piece in seasoned flour mixture, pressing gently to coat. Shake off excess flour.
Fry chicken in batches for 12-15 minutes until golden brown and cooked through (internal temperature 165°F or 74°C).
Transfer fried chicken to a wire rack over a baking sheet to drain excess oil. Let rest for a few minutes before serving.