Slice chicken breasts horizontally to create 4 thin cutlets, about ¼ to ⅜ inch thick. Pound to uniform thickness if needed and season lightly with salt and pepper. Set up three bowls: one with flour, one with eggs whisked with water, and one with breadcrumbs mixed with Parmesan, garlic powder, onion powder, salt, and pepper.

Dredge each cutlet in flour, then egg wash, then breadcrumb mixture, pressing firmly to ensure coating adheres. Let breaded cutlets rest for 5 to 10 minutes before frying.

Heat ½ inch of neutral oil in a large skillet to 350°F. Fry cutlets 2 at a time for 3 to 4 minutes per side until deep golden brown and internal temperature reaches 165°F. Transfer to a wire rack to drain.

Mix softened butter with garlic powder. Split hoagie rolls and spread garlic butter on cut sides. Toast cut-side down in a skillet or under broiler until golden brown, about 2 to 3 minutes.

Preheat broiler to high. Place roll bottoms on a baking sheet and top each with a fried chicken cutlet. Spoon ¼ cup marinara over each cutlet, add 2 slices mozzarella, and sprinkle with Parmesan. Broil for 1 to 2 minutes until cheese is melted and bubbling.

Remove from oven, garnish with fresh herbs if desired, and top with the toasted roll tops. Serve immediately while hot and crispy.