01 - If chicken breasts are thick, gently pound them between plastic wrap to an even thickness of about 1/2 inch using a meat mallet.
02 - In a large bowl, whisk together buttermilk, egg, salt, black pepper, garlic powder, and paprika until well combined.
03 - Submerge chicken breasts in the marinade, cover tightly, and refrigerate for at least 30 minutes or up to 4 hours for deeper flavor penetration.
04 - Arrange two shallow dishes: combine flour, breadcrumbs, salt, smoked paprika, and cayenne pepper in the first; remove chicken from the marinade, letting excess drip off into the second dish.
05 - Dredge each marinated chicken breast in the flour-breadcrumb mixture, pressing firmly to ensure an even, adherent coating on all surfaces.
06 - Pour vegetable oil into a large skillet or frying pan and heat over medium-high until shimmering, reaching approximately 350°F.
07 - Carefully lower coated chicken breasts into the hot oil and fry for 5 to 7 minutes per side until golden brown and crispy, ensuring the internal temperature reaches 165°F.
08 - Transfer fried chicken to a paper towel-lined plate to drain excess oil. Allow to rest for 2 to 3 minutes before serving to lock in juices.