Preheat oven to 375°F; spray a 9x13-inch dish with cooking spray.
Spread 1 cup marinara in prepared dish's bottom.
Layer half the frozen ravioli, half the ricotta, half the remaining marinara, and one-third of mozzarella.
Repeat with remaining ravioli, ricotta, marinara, and another third mozzarella.
Sprinkle with Italian seasoning, garlic, Parmesan, and remaining mozzarella.
Cover tightly with foil; bake 35 minutes. Uncover; bake another 10 minutes, until cheese is bubbly and golden.
Stand 10 minutes before serving.