01 - Slice each chicken breast in half horizontally to create 4 thin fillets of even thickness.
02 - Whisk buttermilk, garlic powder, onion powder, salt, and pepper in a bowl. Add chicken and marinate for at least 15 minutes, up to 4 hours refrigerated for optimal flavor.
03 - Arrange three shallow bowls: one with flour, one with beaten eggs, and one with panko mixed with grated Parmesan.
04 - Remove chicken from marinade. Dredge each piece in flour, shaking off excess. Dip into egg wash, then press firmly into panko-Parmesan mixture to coat thoroughly.
05 - Heat ½ inch of vegetable oil in a large skillet over medium-high heat. Fry chicken pieces for 3–4 minutes per side until golden brown and internal temperature reaches 165°F. Drain on paper towels.
06 - Lightly toast the brioche or sandwich buns until golden.
07 - Spread Caesar dressing on both sides of each bun. Layer bottom bun with shredded romaine, place crispy chicken fillet on top, add additional dressing and shaved Parmesan. Finish with fresh black pepper.
08 - Close sandwiches and serve immediately while chicken remains crispy.