Preheat the oven to 350°F (180°C) and grease a 9"x13" baking dish.
Boil the ravioli until al dente, about 4 minutes. Once done, drain and rinse in cold water (you can toss in a bit of oil to keep them from sticking to each other).
Heat the oil a large sauté pan over medium heat. Add the beef and break it up. Cook until browned, about 7 minutes. Add the marinara sauce and stir to combine.
Pour 1/3 of the meat sauce into the prepared dish and spread to cover the bottom of the dish.
Layer half of the ravioli on top of the sauce. Top with another 1/3 of the sauce and spread evenly. Top with 1 cup of mozzarella.
Layer the remaining ravioli on top. Spread the remaining sauce overtop and sprinkle the remaining 1 cup of mozzarella on top.
Cover with foil and bake for 15 minutes, then remove the foil and bake another 5-10 minutes, until the cheese is melty. Allow to cool slightly and serve.