Fill your deep fryer or a tall pot with vegetable oil and preheat to 400 F (200 C), being careful not to overfill your pot and leaving enough room for the chicken.
Mix together the flour and a teaspoon each of salt and pepper.
Place the chicken thighs in a bowl and coat evenly with buttermilk.
Dredge the chicken thighs in the flour mixture one at a time to thoroughly coat, then place on a plate until the hot oil is ready.
Once your oil is hot enough, carefully place the chicken thighs one at a time into the hot oil and cook until they have reached an internal temperature of 165 F (70 C).
While the chicken is frying, mix the cayenne, paprika and a ¼ teaspoon each of salt and pepper in a metal bowl.
When the chicken is cooked, remove from the deep fryer and place on a wire rack with a baking tray underneath.
While the oil is still hot, using a metal ladle, carefully scoop out about half a cup of the oil and blend with spices. Use a pastry brush to baste the spices on the chicken.
Assemble the sandwiches with the pickles, ranch and lettuce. Serve and enjoy!