Prepare the chicken by pounding it to an even thickness.
Marinate the chicken in buttermilk for at least 1 hour.
Combine flour, garlic powder, onion powder, paprika, salt, and pepper in a shallow dish.
Heat oil in a large skillet over medium-high heat.
Dredge the marinated chicken in the flour mixture, pressing to adhere.
Fry the chicken for 4-5 minutes per side until golden brown.
Remove the chicken and let it drain on paper towels.
Toss the fried chicken in Buffalo sauce.
Toast the burger buns lightly in the same skillet.
Assemble the sandwich with chicken, shredded lettuce, and sliced tomatoes.
Drizzle ranch dressing over the top if desired, and serve.