2 Tbsp. kosher salt, divided
2 tsps. plus 1 Tbsp. black pepper
1-1/2 tsp. paprika
3/4 tsp. cayenne pepper
1/2 tsp. garlic powder
1/2 tsp. onion powder
1 3-4 lb. chicken cut into 10 pieces
1 cup buttermilk
1 large egg
3 cups all-purpose flour
1 Tbsp. cornstarch
Peanut oil (for frying)
Whisk 1 Tbsp. salt, 2 tsp. black pepper, paprika, cayenne, garlic powder, and onion powder in a small bowl. Season chicken with spices. Place chicken in a medium bowl, cover and chill overnight.
Let chicken stand covered at room temperature for 1 hour. Whisk buttermilk, egg, and 1/2 cup water in a medium bowl. Whisk flour, cornstarch, remaining 1 Tbsp. salt, and remaining 1 Tbsp. pepper in a 9 x 13 baking dish.
Pour oil into a 10-12" cast iron skillet to a depth of 3/4". Heat over medium-high heat until thermometer register 350 degrees.
Working with 1 piece at a time, dip chicken buttermilk mixture, allowing excess to drip back into bowl. Dredge in flour mixture; shake off excess. Place 5 pieces of chicken in skillet. Fry, turning with tongs every 1-2 minutes until skin is deep golden brown and chicken registers 165 degrees, about 10 minutes for wings and 12 minutes for thighs legs and breasts.
I went 12-14 minutes for the bigger pieces and dark meat if you don't have a thermometer.
Remove chicken from skillet and transfer to cooling rack. Let cool ten minutes.