01 - In a mixing bowl, combine buttermilk, garlic powder, onion powder, salt, and black pepper. Add chicken fillets, cover, and refrigerate for a minimum of 15 minutes or up to 4 hours for enhanced tenderness.
02 - In a shallow dish, blend flour, panko breadcrumbs, and grated Parmesan cheese. In a separate bowl, beat the eggs until fully combined.
03 - Remove chicken from the marinade. Dredge each fillet first in the flour mixture, then dip in beaten eggs, and once more in the flour mixture for best crispiness.
04 - Heat 1/2 inch of vegetable oil in a skillet or deep fryer to 350°F. Fry chicken fillets 3 to 4 minutes per side, until crisp, golden, and internal temperature reaches 165°F. Drain on paper towels.
05 - Toss shredded romaine lettuce with Caesar dressing in a bowl. Add shaved Parmesan cheese and gently combine.
06 - Optionally, spread unsalted butter on the cut sides of buns and toast in a skillet until golden. Place a piece of fried chicken on each bottom bun, top generously with Caesar salad, and cover with the top bun.
07 - Serve immediately with extra Caesar dressing or lemon wedges if desired.