Preheat the oven to 425°F (220°C). Pat the chicken breasts dry with paper towels. Slice each breast horizontally into two thinner cutlets. Place the cutlets between sheets of plastic wrap or parchment and gently pound them to about 1/2 inch (1.3 cm) thick. Season both sides with 1/2 teaspoon of the salt and 1/4 teaspoon of the black pepper.

Place the flour in one shallow bowl: Put the beaten eggs in a second bowl. In a third bowl, combine the Italian-seasoned breadcrumbs, 1/2 cup Parmesan, Italian seasoning, garlic powder, remaining 1/2 teaspoon salt, and remaining 1/4 teaspoon black pepper.

Coat each chicken cutlet lightly in flour, shaking off the excess. Dip it into the beaten eggs, allowing excess egg to drip back into the bowl. Press the chicken firmly into the breadcrumb mixture so the coating adheres evenly. Place the breaded cutlets on a clean plate.

Heat the olive oil in a large oven-safe skillet over medium to medium-high heat. The oil should shimmer but should not smoke. If using a baking sheet instead, line it with parchment or lightly coat it with cooking spray.

Fry the breaded cutlets in batches if necessary to avoid crowding the skillet. Cook for about 2 to 3 minutes per side, until the coating is crisp and golden brown. The chicken does not need to be fully cooked at this stage.

If your skillet is oven-safe, arrange the browned chicken in the skillet. Otherwise, transfer the cutlets to the prepared baking sheet, leaving space between them.

Spoon about 1 1/2 cups marinara sauce over the tops of the chicken, keeping most of the crispy edges exposed rather than completely covering the breading.

Sprinkle the mozzarella evenly over the marinara, then finish with the remaining 2 tablespoons grated Parmesan.

Bake for about 10 to 15 minutes, until the cheese is melted and bubbling and the thickest part of each chicken cutlet reaches at least 165°F (74°C) on an instant-read thermometer. If the cheese needs more color, switch to the broiler for 1 to 2 minutes, watching closely.

Remove the chicken from the oven and let it rest for about 5 minutes. Serve while the cheese is hot and the coating is still crisp. Spoon additional warm marinara alongside the chicken if desired.