I start by placing the chicken breasts between two sheets of plastic wrap. Using a meat mallet, I pound them to an even thickness of about three-quarters of an inch. This helps the chicken cook through evenly without drying out the edges.
In a large bowl, I whisk together the buttermilk, hot sauce, paprika, garlic powder, salt, and pepper. This marinade does more than add flavor; the buttermilk's acidity gently breaks down the surface of the chicken, keeping it tender through frying.
I submerge the chicken fully in the marinade, cover the bowl, and refrigerate it for at least an hour. If I have time, I let it sit overnight, since the flavor only gets better the longer it rests.
While the chicken marinates, I combine the flour, cornstarch, cayenne pepper, and onion powder in a shallow dish. The cornstarch is what gives the crust its light, shattering crunch instead of a heavy, doughy texture.
I remove the chicken from the marinade, letting the excess drip off, then press each piece firmly into the flour mixture. Pressing it in on all sides helps the coating stick properly during frying.
I pour oil into a deep skillet until it's about two inches deep and heat it to 350°F. Getting the temperature right matters; oil that's too cool makes the coating greasy instead of crisp.
I carefully lower the coated chicken into the hot oil and fry for about five to six minutes per side, until it's deep golden brown. I always check that the internal temperature reaches 165°F before removing it.
Once cooked, I transfer the chicken to a wire rack instead of a paper towel. This keeps air circulating underneath so the crust doesn't turn soggy while it rests for a couple of minutes.
I toast the buns lightly, spread mayonnaise on both halves, layer on the shredded lettuce, and place the crispy chicken on top. A few pickle slices go on before I close it up and serve right away.