Spaghetti Casserole
Yield: 8 servings
Classic Italian flavors come together easily in casserole form for a dish the whole family will enjoy.


  • 1½ pounds lean ground beef
  • 1 cup diced yellow onion
  • 1 (28-ounce) can diced tomatoes, with juices (or whole tomatoes, cut up)
  • 1 (24-28-ounce) jar spaghetti sauce (I like it a little saucier, but if your favorite jarred pasta comes in a 24-ounce jar, the outcome will still be good.)
  • 5-6 ounces (about 2 cups) fresh, sliced mushrooms (may omit if not a fan)
  • 1½ teaspoons dried oregano
  • 1½ teaspoons kosher salt (use ¼ teaspoon less if using table salt)
  • 1 teaspoon (4g) sugar*
  • 8 ounces spaghetti**, broken in thirds (use gluten-free, if needed)
  • 2 cups (8 ounces) shredded mozzarella cheese
  • ⅓ cup (27g) grated Parmesan cheese
  • Parsley for garnish (optional)


  1. Cook the sauce: In a 14-inch skillet or deep saucepan (a standard 12-inch skillet will be very full at the end), sauté the ground beef and onions until the beef is no longer pink. Drain if necessary. Stir in the tomatoes with their juices, spaghetti sauce, mushrooms, and seasonings. Bring to a boil, and then reduce the heat and maintain a gentle simmer for 20 minutes, uncovered. (Tip: You want the wateriness of the diced tomato juice to concentrate, but to maintain a good level of sauciness in the final product, you don’t want the sauce to reduce and thicken too much.)

    Cook the pasta: Meanwhile, cook the broken pasta in salted water according to package directions. Drain well.

    Assemble the casserole: Remove the sauce from the heat and stir in the spaghetti. Place half of the mixture in a 9×13 baking dish (I don’t grease), and then sprinkle with half of the mozzarella. Repeat with the remaining spaghetti mixture and cheese. Sprinkle the Parmesan on top.

    Make-ahead tip: At this point, the casserole may be cooled, covered, and refrigerated for several days or frozen for several months.

    Bake: Preheat the oven to 375℉ and bake, uncovered, for 20-30 minutes, or until hot throughout and lightly golden on top. If the casserole has been refrigerated, let it sit at room temperature while the oven is preheating and cook for a few extra minutes, as needed. If frozen, thaw completely before baking.

    Serve: Garnish with optional fresh parsley and serve.

    Storage: Refrigerate leftovers, covered or in an airtight container, for up to 5 days.


* The original recipe called for 2 teaspoons of sugar. The purpose is to balance the more acidic flavor of canned tomatoes. I’ve reduced the amount to 1 teaspoon over time. If you prefer, you may use the higher amount–or omit altogether if preferred.
** A half pound of spaghetti might not seem like a lot for a whole casserole, but do not fear. It’s plenty. If you use more, the balance of sauce and meat to noodles will be thrown off.


  • For a saucier end result, you could increase the marinara sauce to 4 cups, or serve with extra of your favorite sauce on the side.
  • Use a mix of ground beef and Italian sausage.
  • Substitute dried Italian seasoning for the dried oregano or use 1½ tablespoons minced fresh oregano.
  • Replace the shredded mozzarella cheese with an Italian blend.

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