01 - Place chicken breasts between two sheets of plastic wrap and gently pound with a meat mallet to an even 1/2-inch thickness throughout.
02 - In a mixing bowl, whisk together the buttermilk, salt, black pepper, and garlic powder until well combined.
03 - Submerge the pounded chicken breasts in the buttermilk mixture, turning to coat evenly. Cover and refrigerate for at least 30 minutes, or up to overnight for deeper flavor penetration.
04 - In a shallow dish, combine the all-purpose flour, paprika, cayenne pepper, onion powder, salt, and black pepper. Whisk until evenly distributed.
05 - Pour vegetable oil into a large skillet to a depth of about 1/4 inch. Heat over medium-high heat until the oil reaches 350°F. Use a thermometer to monitor temperature.
06 - Remove each breast from the buttermilk marinade, allowing excess liquid to drip off. Press each piece firmly into the seasoned flour, flipping and pressing again to ensure full, even coating on all sides.
07 - Carefully lower the breaded chicken into the hot oil, working in batches to avoid overcrowding. Fry for 6 to 7 minutes per side until deeply golden brown and the internal temperature reads 165°F at the thickest part.
08 - Transfer fried chicken to a wire rack set over a sheet pan or a paper towel-lined plate to drain excess oil. Allow to rest for 5 minutes before serving to let juices redistribute.