01 - If the chicken breasts are thick, place them between sheets of plastic wrap and gently pound to an even ½-inch thickness using a meat mallet.
02 - In a large mixing bowl, whisk together the buttermilk, egg, salt, black pepper, garlic powder, and paprika until well combined.
03 - Submerge the chicken breasts in the marinade, cover the bowl, and refrigerate for at least 30 minutes or up to 4 hours for deeper flavor penetration.
04 - In a shallow dish, combine the flour, panko breadcrumbs, salt, smoked paprika, and cayenne pepper. Mix thoroughly. Remove the chicken from the marinade, letting excess drip off.
05 - Dredge each marinated chicken breast in the flour-breadcrumb mixture, pressing firmly on all sides to ensure an even, adherent coating.
06 - Pour vegetable oil into a large skillet or frying pan to a depth of about ½ inch. Heat over medium-high until the oil shimmers and reaches 350°F.
07 - Carefully lower the coated chicken breasts into the hot oil. Fry for 5 to 7 minutes per side until deeply golden and crispy, and the internal temperature registers 165°F.
08 - Transfer the fried chicken to a paper towel-lined plate to drain excess oil. Let rest for 2 to 3 minutes before serving.