Mix all the ingredients of the marinade in a large bowl (hot sauce, salt, pepper, and buttermilk)
Leave the chicken thighs in the marinade for at least 3-4 hours, or overnight, after covering the bowl tightly with plastic wrap.
Now, for the dredging mix. In another large bowl, mix the cornstarch, flour, garlic powder, dried oregano, white pepper, salt, paprika and cayenne pepper.
Fill 2-inches of a large pan with vegetable oil. Set the pan on medium-high heat flame, wait for the oil to heat till 350˚F (177˚C).
While the oil is heating, remove each chicken thigh from the marinade and cover it in the dredging mix thoroughly, making sure to shake off the excess mix.
Lower each piece in the hot oil carefully. Make sure the pan is not overcrowded.
Leave them to fry for 10-14 minutes with constant turning to each side every 2 minutes. They should have this appetizing golden brown color and an internal temperature of 165˚F.
When they are cooked enough, remove each piece from the oil. Place the pieces on a cooling rack to remove the excess oil and rest for 10 minutes.
Prepare your sauce by mixing all the ingredients in a bowl.
Grill your burger buns till they gain that golden brown color, then spread the butter on the browned side. Cover the lower bun with the prepared sauce, then place the fried chicken, lettuce and more burger sauce.
Cover the burger with the top bun. Serve with fries and enjoy.