01 - Place chicken breasts between two sheets of plastic wrap and pound to 1/2-inch thickness using a meat mallet for even cooking.
02 - In a large bowl, whisk buttermilk and hot sauce. Add chicken, turning to coat thoroughly. Cover and refrigerate for at least 1 hour or up to overnight for maximum tenderness.
03 - In a shallow dish, combine flour, cornstarch, paprika, garlic powder, onion powder, salt, black pepper, cayenne, and thyme. Mix well to distribute spices evenly.
04 - In a separate bowl, whisk eggs and milk together until fully combined and smooth.
05 - Remove chicken from buttermilk, allowing excess to drip off. Dredge in seasoned flour, dip in egg wash, then dredge again in seasoned flour, pressing lightly to adhere coating thoroughly.
06 - Heat oil in a deep skillet or Dutch oven to 350°F. Maintain temperature throughout frying for optimal crispiness.
07 - Fry chicken in batches without overcrowding for 5-7 minutes per side until golden brown and internal temperature reaches 165°F.
08 - Transfer to a wire rack or paper towels to drain excess oil. Let rest for 5 minutes before serving to retain juices.