Marinate the chicken in buttermilk for at least 1 hour, or overnight for best results.
Prepare the breading station with flour, garlic powder, onion powder, paprika, and cayenne.
Preheat oil in a deep skillet or fryer to 350°F (175°C).
Remove the chicken from the buttermilk and dredge in the flour mixture.
Fry the chicken pieces for about 5-7 minutes on each side, or until golden brown and cooked through.
Remove the chicken and let it rest on a paper towel to absorb excess oil.
Toss the fried chicken in buffalo sauce until fully coated.
Toast the burger buns in the residual heat of the frying pan until golden.
Assemble the sandwich by placing the lettuce and tomato on the bottom bun, followed by the buffalo chicken, and drizzle dressing on top before placing the top bun.
Serve immediately with additional buffalo sauce if desired.