Pound Chicken: One by one lay a chicken thigh on a chopping board and rest over cling film. Pinch around the edges to avoid any moisture escaping, then pound with a rolling pin, mallet or even a heavy pan. You want them fairly thin, but not so thin they start breaking apart. The main goal is to achieve even thickness across the thigh.
Marinate: In a medium sized mixing bowl combine 1 cup buttermilk with 1 tsp salt & paprika, 1/2 tsp onion powder, garlic powder, white pepper and cayenne pepper. Add in chicken thighs and use your tongs to ensure they'll all evenly coated. Cover with cling film then marinate in the fridge. I highly recommend a minimum of 4 hours (up to overnight), but just as long as you have time for. Take the chicken out the fridge 30mins before needed to bring close to room temp.
Dredge: In a shallow dish or curved tray, combine 1 3/4 cups flour with 2 tsp paprika, 1 tsp baking powder, salt and oregano, 1/2 tsp onion powder, garlic powder and cayenne pepper and 1/4 tsp black pepper. One by one dredge the thighs through the flour, making sure you completely coat each time. Really get in all the cracks and crevices of the chicken to create lots of craggy bits on the batter. Place to one side.
Fry: In a large pot or deep pan heat up 3-4 cups oil to 180C/356F. Place in 1 thigh and fry for 3-4mins each side, or until deep golden and crunchy. The internal temp of the chicken should reach 75C/165F (will continue cooking slightly as it rests). The temp of the oil will likely drop when the chicken starts frying, and that's fine, but make sure the temp stays at around 165C/300F as the chicken fries (a medium flame should obtain this). Carefully remove and rest on wire rack with paper towels underneath (don't place directly on paper towel or they'll lose crispiness). Bring oil temp back up to 180C/356F and fry the next thigh.
Serve: In a small pot whip up your sriracha honey mayo, then stack the sandwiches in the following order - Bottom bun, mayo, lettuce, chicken, pickles, top bun (spread with mayo). Enjoy!