Step 1: In a large bowl or resealable plastic bag, combine the chicken pieces and buttermilk. Ensure all chicken is coated. Cover and refrigerate for at least 4 hours, or preferably overnight, for maximum tenderness and flavor.
Step 2: In a separate shallow dish or bowl, whisk together the all-purpose flour, salt, black pepper, paprika, garlic powder, onion powder, and cayenne pepper (if using).
Step 3: Remove chicken from the buttermilk, allowing excess to drip off. Dredge each piece thoroughly in the seasoned flour mixture, pressing to ensure a thick, even coating. Set coated chicken aside on a wire rack while you prepare the oil.
Step 4: In a large, heavy-bottomed pot or Dutch oven, pour enough oil to reach about 2-3 inches deep. Heat the oil over medium-high heat until it reaches 325-350°F (160-175°C). Use a thermometer to monitor the temperature.
Step 5: Carefully place 2-3 pieces of chicken into the hot oil, ensuring not to overcrowd the pot. Fry for 6-8 minutes per side, or until golden brown and the internal temperature reaches 165°F (74°C). The cooking time will vary depending on the size of the chicken pieces.
Step 6: Once cooked, remove the fried chicken from the oil and place it on a wire rack set over a baking sheet to drain excess oil. This helps maintain crispness. Repeat with remaining chicken pieces, ensuring the oil returns to temperature between batches.
Step 7: Serve your classic buttermilk fried chicken immediately with your favorite sides and enjoy!