Mix dry ingredients in a large mixing bowl with a whisk.
Mix buttermilk and eggs in a second large mixing bowl.
Fill cast iron pan with about 1/2" of oil and preheat over medium heat.
While the oil heats, cut chicken breasts into filets or nugget sized chunks.
Rinse the chicken and pat dry with a paper towel.
Place chicken pieces in buttermilk and egg wash.
One at a time, remove chicken from buttermilk and egg wash and coat with dry batter mixture.
Place chicken in oil and fry for 3-4 minutes on each side.
Remove the crispiest fried chicken from the oil and place on a paper towel lined plate.