In a large bowl, combine the buttermilk, paprika, garlic powder, onion powder, salt, black pepper, and cayenne pepper (if using). Whisk together until smooth.

Flatten the chicken breasts using a meat mallet to an even thickness. Place them in the buttermilk mixture, cover, and marinate for at least 30 minutes (or up to 2 hours in the refrigerator).

Prepare your breading station. In a shallow dish, combine the flour with a pinch of salt and pepper. In another dish, mix the breadcrumbs with a bit of salt.

Heat about 1 inch of vegetable oil in a large skillet over medium heat until hot (around 350°F).

Remove the first chicken breast from the buttermilk, allowing excess to drip off. Dredge in the flour mixture, then dip again in the buttermilk, and finally coat in the breadcrumbs, pressing to adhere.

Carefully place breaded chicken breasts into the hot oil, cooking in batches if necessary. Fry for 5-7 minutes per side, or until golden brown and cooked through (internal temperature should reach 165°F).

Once cooked, transfer to a paper towel-lined plate to drain excess oil.

Toast the burger buns in the same skillet until golden.

In a small bowl, mix the mayonnaise with hot sauce (if using).

Assemble each sandwich by spreading the spicy mayo on the bottom bun, adding the lettuce, a fried chicken breast, and a slice of tomato. Finish with the top bun.

Serve immediately and enjoy your crispy chicken sandwiches!