Lightly pound each chicken breast between two pieces of plastic wrap until it reaches about ¼ inch thickness. prep

In a large ziplock bag, combine the buttermilk, pepper, salt, and cayenne pepper. Add the chicken, seal the bag, and refrigerate for at least an hour (overnight works best). prep

Whisk together flour, cornstarch, baking powder, and salt in a large bowl. mix

Take each chicken breast and dredge it in the flour mixture, pressing the flour into the chicken. Place it on a wire rack over a rimmed baking sheet. Repeat for all chicken breasts. Refrigerate uncovered for 30 minutes. prep

Set up a clean wire rack on a rimmed baking sheet, placing paper towels on one side for draining. prep

Heat vegetable oil in a cast-iron skillet over medium-high heat, bringing the temperature to 375ºF. Keep oil temperature between 325ºF and 350ºF. prep

Coat each chicken breast in the flour mixture again, ensuring it’s fully covered. Carefully place two chicken breasts into the hot oil and cook for 3-5 minutes on each side until golden brown and the internal temperature reaches 160ºF. Remove and drain on the paper towel-covered rack. Continue with remaining chicken breasts. cook

In a saucepan, melt butter over medium heat. Whisk in flour and cook for about 1 minute. Gradually add the milk, whisking constantly, until the gravy thickens (about 3 minutes). Finish by adding salt, pepper, and cayenne. If the gravy is too thick, add a bit more milk. mix