Optional garnish: chopped fresh basil, parsley, or other herbs
Instructions
Preheat oven to 400°F. Grease a 9 x 13-inch baking dish or lightly coat with nonstick cooking spray.
In a large measuring cup or bowl, whisk together the marinara sauce, water, and a few pinches of salt and pepper. Pour a small amount of the sauce mixture into the bottom of the prepared dish (just enough to coat in a thin layer).
Arrange about half of the frozen tortellini in a single layer in the dish. Pour about half of the remaining sauce mixture over top, and sprinkle with ½ cup of grated mozzarella.
Arrange the remaining tortellini in another layer in the pan. Pour the remaining sauce over top. Press down gently to make sure that all of the tortellini are coated in sauce. Sprinkle remaining mozzarella over top and sprinkle with Parmesan cheese.
Cover tightly and bake for 20 minutes. Remove cover and continue baking until the tortellini is al dente, about for 15-20 more minutes. Transfer the dish to the broiler for a couple of minutes if you like the cheese browned and crispy on top.
Let stand 5-10 minutes before serving. The pasta will continue to absorb some of the sauce. Garnish with additional Parmesan cheese and chopped fresh herbs, if desired.
Notes
The tortellini absorbs some of the liquid as it bakes in the pan, which is why we add a little bit of extra water to the marinara sauce. If you prefer a thicker sauce, you can omit the water (or decrease the total amount).
The total baking time will vary depending on a number of different factors, including the type/size/brand of tortellini, the type of pan that you use, and on your individual oven. As a result, keep an eye on the tortellini as it bakes. You'll know it's done when the pasta is al dente (tender, with a firm bite). The tortellini will continue to cook and soften as it sits in the hot sauce, so you don't want to overcook it and end up with mushy or torn tortellini.
Season the dish with Italian seasoning or other herbs and spices of your choice. Some crushed red pepper flakes add a nice, spicy kick, and fresh herbs provide a bright, finishing touch. Good options include basil, parsley, and oregano.
Use any flavor of tortellini. I like cheese tortellini, but a meat-filled tortellini or spinach tortellini will also work well.
Add meat, such as cooked, diced chicken, browned ground beef, ground turkey, or Italian sausage, or cooked meatballs. You can also make the baked tortellini with meat sauce rather than plain marinara sauce.
Stir in some veggies, such as fresh or frozen (thawed and squeezed dry) spinach, sauteed mushrooms, onion, or zucchini, or parboiled broccoli.
If using refrigerated/fresh tortellini, the cooking time will be about half as long. As a result, you can skip the cover and just bake the tortellini uncovered for a total of about 15-20 minutes, or until tender.