Preheat oven to 375°F (190°C). Lightly oil a 9x13-inch baking dish.

If using raw frozen ravioli that require boiling: bring a large pot of salted water to a boil and cook ravioli 1–2 minutes less than package directions; drain and toss gently with a splash of olive oil. If ravioli are fresh or labeled 'no-boil,' you can layer them directly.

In a skillet, warm olive oil over medium heat. Add garlic and sauté 30–45 seconds until fragrant. Stir in marinara and oregano; simmer 3–4 minutes. Taste and season with salt and pepper.

Spread 1 cup of sauce on the bottom of the baking dish.

Arrange half the ravioli in a single layer over the sauce.

Dollop half the ricotta over the ravioli in spoonfuls. Sprinkle 1.5 cups mozzarella and 1/4 cup Parmesan.

Repeat: spread another cup of sauce, top with remaining ravioli, remaining ricotta, remaining mozzarella, and the final Parmesan. Spoon any extra sauce over the top.

Cover loosely with foil and bake for 20 minutes. Remove foil and bake another 8–12 minutes until cheese is bubbly and lightly browned.

Let it rest for 5–10 minutes before slicing. Garnish with chopped basil or parsley.