Prep the pasta water, oven and baking dish. Bring a large pot of generously-salted water to a boil. Heat the oven to 400°F. Mist a 9x13-inch baking dish with oil.

Cook the meat and veggies. Cook the pancetta in a large sauté pan or stockpot until browned, stirring occasionally. Use a slotted spoon to transfer the pancetta to a clean bowl and set aside. Add the Italian sausage and onion and cook until browned, breaking the sausage up with a wooden spoon as it cooks. Add the garlic, crushed red pepper flakes and oregano and sauté for 2 more minutes, stirring frequently.

Cook the pasta. Add the pasta to the boiling water and cook until it’s about 1 minute shy of al dente. (The pasta will continue to cook in the oven.) Drain the pasta and return it to the stockpot.

Finish the sauce. While the pasta is cooking, carefully add in the marinara sauce, spinach and cooked pancetta to the meat mixture and stir to combine until the spinach has wilted. One the pasta has been drained, pour the sauce into the stockpot with the pasta and gently toss to combine.

Layer in a pan. Add about half of the pasta mixture to the pan in an even layer. Sprinkle evenly with half of the mozzarella and half of the Parmesan. Add the remaining pasta and sprinkle evenly with the remaining mozzarella.

Bake. Bake for 20 minutes or until the sauce is bubbly and the cheese begins to brown. (If you’d like the cheese even more golden, you can turn on the broiler for a minute or two until it starts to brown, keeping a very close eye so that it does not burn.)

Serve. Sprinkle with the remaining Parmesan and basil or parsley, serve up nice and hot, and enjoy!