Beat the eggs in a shallow bowl. Mix breadcrumbs, ¼ cup Parmesan, garlic powder, oregano, salt, and pepper in a second bowl. Dip each cutlet in egg, then press into the breadcrumb mixture to coat completely.

Spread 1 cup marinara in a 9x13-inch baking dish. Place breaded cutlets in a single layer over the sauce. Top with the remaining 1 cup marinara, mozzarella slices, and the remaining ¼ cup Parmesan.

Drizzle the olive oil over the top. Bake at 400°F (200°C) for 25 to 30 minutes, until the cheese is melted and bubbly and the chicken is cooked through.

Let the casserole rest for 5 minutes, then slice into portions and serve with extra sauce from the dish.