In a shallow bowl, whisk together the buttermilk and hot sauce. Submerge the chicken pieces and refrigerate for at least 30 minutes, or up to 2 hours. This tenderizes the meat and adds a gentle zing to the flavor.
While the chicken marinates, set up your dredging station. In one dish, mix flour with paprika, garlic powder, salt, black pepper, and cayenne if using. In another dish, have a dry, clean plate ready for the coated chicken.
Remove the chicken from the marinade. Let excess liquid drip off, then dredge each piece in the seasoned flour, pressing gently so it sticks well. Shake off any excess flour and place the coated chicken on a rack for a minute to set the crust.
Heat the oil in a heavy skillet or Dutch oven to 350°F (175°C). You should see a steady shimmer, not a smoking pool.
Carefully drop a few coated chicken pieces into the oil. Don’t crowd the pan. Fry for about 4–5 minutes per side, adjusting heat to maintain a steady temperature. The crust should be golden brown and the internal temperature should reach 165°F (74°C).
Remove the chicken and let it rest on a rack or paper towels for a few minutes. While it rests, lightly toast the buns.
Spread mayonnaise or your preferred sandwich spread on the buns. Layer with pickles and lettuce if you like, then add the fried chicken. Top with the other half of the bun and serve immediately.