Heat oil in a large saucepan over medium heat. Then add in the garlic paste and stir frequently for about one minute.
¼ cup olive oil, 2 tablespoons garlic paste
Add in the tomatoes, salt, basil, oregano, and red pepper flakes and simmer for 30 minutes. Occasionally, use a wooden spoon or hand masher to help break down the tomatoes.
2 (28 oz.) cans whole San Marzano Style tomatoes, 1 teaspoon kosher salt, ½ teaspoon dried basil, ½ teaspoon dried oregano, ⅛ teaspoon crushed red pepper
Add onions to a separate pan with a tablespoon of olive oil and cook over medium heat until translucent, about 4 to 5 minutes.
1 tablespoon olive oil, ½ yellow onion
Add ground beef to the onions and cook until browned all over. Drain and transfer the beef and onions into the tomato sauce mixture.
1 pound ground beef
Add in the Parmesan cheese rind and simmer for another 15 minutes. Remove the soft rind before using the sauce. This should yield around 10 cups of sauce.
1 Parmesan rind
Combine the ricotta, egg, salt, and pepper in a medium bowl and set aside.
16 ounces ricotta cheese, 1 large egg, 1 teaspoon salt, ½ teaspoon ground black pepper
In a separate bowl, combine the shredded parmesan and mozzarella and set aside.
1 cup finely grated parmesan, 2 cups shredded mozzarella
Preheat the oven to 350°F and grease a 9x13-inch pan with cooking spray.
Layer the bottom of the pan with a thin layer of sauce, about 1 cup.
Top the sauce with a layer of ravioli, about 20 ravioli.
40 ounces cheese ravioli
Top the ravioli with a layer of sauce, about 2 cups.
Top the sauce with half of the ricotta mixture then 1 cup of the shredded cheese mix.
Layer on another 2 cups of sauce, then another layer of ravioli, then another 2 cups of sauce.
Add the remaining ricotta mixture and top with another cup of the shredded cheese mixture.
Add a layer of sauce, then the remaining ravioli, then another layer of the remaining sauce, and then sprinkle the last of the shredded cheese mixture over the top. These last layers are optional depending on size, see recipe notes.
Cover the pan with aluminum foil and bake for 30 minutes. Remove the foil and bake for an additional 15 minutes or until the top is golden and bubbly.