Place a wire rack on a large rimmed baking sheet; spray with cooking spray.
For chicken: In a large bowl, whisk together buttermilk, pickle juice, eggs, 2 teaspoons salt, and ½ teaspoon black pepper until combined. Add chicken to bowl, turning to coat. Let stand at room temperature 30 minutes.
In a large cast-iron Dutch oven, pour oil to a depth of 3 inches. Heat oil over medium heat until a deep-fry thermometer registers 350°.
In a large shallow dish, whisk together flour, remaining 1 tablespoon salt, and remaining 1 teaspoon black pepper. Remove chicken from buttermilk mixture. Dredge chicken in flour mixture, shaking off excess.
Working in batches, fry chicken, turning occasionally, until golden brown and a meat thermometer inserted in thickest portion registers 160°, about 12 minutes. Transfer chicken to prepared pan.
For hot coating: In a small bowl, stir together 6 tablespoons reserved oil, ground red pepper, brown sugar, crushed red pepper, salt, dill, and garlic powder. Using a brush, dab oil mixture over one side of cooked chicken. Serve immediately.
Recipe by Southern Cast Iron at https://southerncastiron.com/hot-chicken-wings/