Chop the garlic into fine minced pieces and measure out the marinara sauce. Preheat your oven to 375°F (190°C).
1 package frozen ravioli
Heat the olive oil in a large skillet over medium heat. Add the minced garlic and sauté until it becomes fragrant and golden, about 1-2 minutes, stirring constantly.
1 package frozen ravioli
Add the marinara sauce to the skillet and stir to combine with the sautéed garlic. Season with salt, pepper, and oregano. Simmer the sauce until it slightly thickens, about 3-5 minutes, watching for bubbling and aroma.
1 package frozen ravioli
Spread a thin layer of the sauce evenly across the bottom of a baking dish. Arrange the frozen ravioli in a single layer over the sauce, ensuring they do not overlap too much.
1 package frozen ravioli
Spoon the remaining sauce evenly over the ravioli, then sprinkle the shredded mozzarella cheese generously on top. Cover the dish with aluminum foil.
1 package frozen ravioli
Bake in the preheated oven for 20-25 minutes, or until the cheese is melted, bubbly, and slightly golden. Carefully remove the foil during the last 5 minutes to allow the cheese to crisp up.