Slice the chicken breasts horizontally into fillets or use tenderloins.

In a bowl, combine buttermilk, pickle juice, sriracha, paprika, white pepper, garlic powder, salt, and egg.

Add the chicken pieces, making sure they’re fully submerged.

Cover and refrigerate for at least 2 hours or overnight for best results.

In a separate bowl, mix all the coating ingredients, flours, spices, and salt.

Add about 1 tablespoon of the buttermilk marinade into the dry mixture and mix lightly with your hands to form small clumps. This gives the chicken that craggy, crunchy texture when fried.

Remove each chicken piece from the marinade, allowing excess to drip off.

Dredge thoroughly in the coating mixture, pressing it in well to create texture.

Let coated chicken rest on a tray for 10–15 minutes before frying.

Heat oil in a heavy-bottomed pan to 170–175°C (340–350°F).

Fry each piece for 4–6 minutes per side, depending on thickness, until golden brown and cooked through.

Place on a wire rack to drain excess oil.

In a small bowl, mix mayonnaise, ketchup, mustard, pickle juice, salt, and pepper.

Adjust to taste, add more mustard for tang or ketchup for sweetness.

Toast the brioche buns lightly in butter.

Spread burger sauce on both sides of the bun.

Add pickles, then place the crispy chicken on top.

Close with the top bun and serve immediately!