Cheesy Baked Spaghetti Casserole
Spaghetti and rich meat sauce baked under a blanket of bubbling mozzarella and parmesan. A crowd-pleasing Italian-American casserole that feeds the whole family and makes ahead beautifully.
- 1 lb spaghetti
- 1 lb ground beef
- 1 small onion, diced
- 3 cups marinara sauce
- 2 cups shredded mozzarella cheese
- 1 cup shredded parmesan cheese
- 1 teaspoon garlic powder
- 1 teaspoon Italian seasoning
- ½ teaspoon salt
- ½ teaspoon black pepper
- 1 tablespoon fresh parsley, chopped
- Heat your oven to 375°F (190°C) and lightly grease a large baking dish — a 9×13 inch dish works perfectly for this quantity. Getting the oven up to temperature before you start means it will be ready the moment the casserole is assembled.
- Bring a large pot of well-salted water to a boil and cook the spaghetti until just al dente — pull it a minute or two before the package suggests, as it will continue cooking in the oven. Drain and set aside; toss with a tiny splash of olive oil to prevent clumping while you work on the sauce.
- Place a large skillet over medium-high heat and add the ground beef and diced onion together. Break the meat up with a wooden spoon as it cooks, stirring regularly, until the beef is fully browned and the onion has softened and turned translucent — about 8 to 10 minutes. Tilt the pan and spoon away any excess rendered fat before continuing.
- Add the marinara sauce, garlic powder, Italian seasoning, salt, and black pepper directly to the beef and onion mixture. Stir everything together thoroughly and bring to a gentle simmer over medium heat. Let the sauce cook for 5 minutes, stirring occasionally, to allow the flavours to meld and the sauce to deepen slightly in colour and intensity.
- Spread the cooked spaghetti evenly across the base of your prepared baking dish. Pour the meat sauce over the top and fold gently with a spoon or tongs to combine — you want the pasta and sauce roughly integrated without mashing the spaghetti. Aim for an even distribution so every serving gets a good ratio of pasta to meat.
- Scatter the shredded mozzarella evenly across the surface, then follow with the parmesan in an even layer on top. The two-cheese combination gives you stretch from the mozzarella and sharp, salty depth from the parmesan — don't be tempted to skimp on either.
- Slide the dish into the preheated oven and bake uncovered for 25 to 30 minutes, until the cheese is fully melted, bubbling at the edges, and beginning to turn golden in patches. For a more deeply coloured, slightly crispy top, switch the oven to the broil setting for the final 2 minutes — watch it closely, as it can go from golden to burnt quickly under the broiler.
- Remove the casserole from the oven and let it rest on the counter for at least 10 minutes before cutting. This resting time allows the layers to settle and firm up, making it far easier to slice and serve in clean portions. Scatter the chopped fresh parsley over the top just before serving for a pop of colour and freshness.
Chef's Note: Baked spaghetti casserole is one of those reliably satisfying dishes that every home cook should have in their repertoire. It takes the flavours of a classic spaghetti bolognese and transforms them into something sliceable, shareable, and deeply comforting — the kind of thing that disappears quickly at a family dinner and prompts requests for the recipe. The key technique is undercooking the pasta before it goes into the oven; fully cooked spaghetti will turn mushy after 30 minutes of baking, while al dente pasta emerges perfectly tender with a little bite still intact.
This dish is a genuine make-ahead winner. You can assemble the entire casserole — pasta, sauce, and cheese — up to 24 hours in advance, cover it tightly with foil, and refrigerate it until you're ready to bake. Add an extra 10 minutes to the baking time if going straight from the fridge to the oven. Leftovers reheat beautifully covered with foil at 350°F for 15 to 20 minutes, or in portions in the microwave. For a richer result, stir a cup of ricotta into the pasta layer before adding the meat sauce — it adds creaminess and helps bind everything together into more satisfying slices.
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