01 -
Heat oven to 400°F. Lightly grease a 9 x 13-inch baking pan with cooking spray.
02 -
Heat a large sauté pan over medium-high heat. Add the Italian sausage and cook until browned, crumbling the meat as it cooks. Transfer the sausage to a clean plate and set aside.
03 -
Reserve about 1 tablespoon of the sausage grease in the pan and discard the rest. Add the onion and garlic, and sauté for 4-5 minutes until softened. Add the marinara sauce and cooked sausage to the pan and stir to combine. Turn off the heat.
04 -
Spread about 1 cup of the meat sauce on the bottom of the baking dish. Layer in each of the following ingredients: one package of ravioli, all of the ricotta, half of the mozzarella, half of the remaining meat sauce, the second package of ravioli, all of the remaining meat sauce, and all of the remaining mozzarella.
05 -
Loosely cover the pan with aluminum foil, ideally without touching the cheese. Bake for 35 minutes. Uncover and bake for another 10 minutes. Turn on the broiler and broil for 2-3 minutes until the cheese is lightly golden and bubbly.
06 -
Sprinkle the top of the lasagna with Parmesan cheese and basil. Serve warm while the cheese is gooey.