In a large bowl, combine buttermilk, 2 tablespoons salt, 1 teaspoon black pepper, 1 teaspoon paprika, and 1 teaspoon garlic powder. Add chicken pieces, ensuring they are fully submerged.

Cover the bowl and refrigerate for at least 4 hours, or preferably overnight. In a separate shallow dish, whisk together flour, cornstarch, 1 tablespoon salt, and 1 teaspoon black pepper.

Heat vegetable oil in a large, heavy-bottomed pot or Dutch oven to 350°F (175°C). Remove chicken from buttermilk, allowing excess to drip off, then dredge each piece in the flour mixture, ensuring it is fully coated.

Dip the chicken back into the buttermilk briefly, then dredge thoroughly in the flour mixture a second time. Carefully place a few chicken pieces into the hot oil, making sure not to overcrowd the pot.

Fry for 6-8 minutes per side, or until golden brown and cooked through (internal temperature of 165°F/74°C). Remove chicken and place on a wire rack set over paper towels to drain excess oil. Repeat with remaining chicken and serve hot.