Preheat the oven to 400 degrees F and lightly grease a 9x13 baking dish.
Cover the bottom of the dish with a thin layer of spaghetti sauce. Spread half of the ravioli, in a single layer, overlapping slightly if needed, over the spaghetti sauce. Top the ravioli with half of the remaining sauce, spreading to cover, and then top with half of the mozzarella cheese. Sprinkle the cheese with a ½ teaspoon each of garlic powder and oregano. Repeat the layers.
Cover the baking dish with foil and bake for 20 minutes. Uncover and bake for additional 10 minutes if using fresh or defrosted ravioli and 20 minutes if using frozen ravioli.
Let rest for 10-15 minutes before serving with additional parmesan cheese if desired.
Serve with Parmesan Cheese if desired.
Notes
Ravioli: Use fresh or frozen cheese or spinach and cheese ravioli.Adding Meat: Add a layer of thinly sliced pepperoni in between the layers of ravioli or prepare a quick meat sauce by browning 1 pound of ground Italian sausage or lean ground beef in a large skillet until cooked through. Stir in the spaghetti sauce and use as directed in the casserole.Storage: Store leftovers in an airtight container in the refrigerator for up to 5 days. Reheat individual servings by heating for 30-45 seconds in the microwave on a heat-safe plate covered with a damp paper towel.