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Jump to RecipeBaked spaghetti casserole is what happens when a pot of spaghetti with meat sauce goes into the oven under a blanket of mozzarella and Parmesan. The noodles soak up the sauce, the edges turn a little crispy, and the cheese on top gets golden and bubbly. It feeds eight people from one 9×13 dish, it reheats beautifully, and it’s one of the easiest ways I know to turn a basic weeknight dinner into something the whole family gets excited about.
This version keeps everything that made the original recipe on this blog so popular (lean ground beef, sweet bell pepper, jarred marinara, and a double layer of cheese), but I’ve tightened up the method so the pasta never turns mushy and the sauce tastes like it simmered for hours instead of ten minutes.
Why This Baked Spaghetti Works
- The pasta is cooked 2 minutes short. It finishes in the oven, so it stays tender with a little bite instead of going soft.
- The sauce is a bit looser than you’d serve on the stovetop. Spaghetti keeps drinking sauce while it bakes, so starting slightly saucy means a moist casserole at the end.
- Cheese goes in two places. A handful of mozzarella is tossed through the noodles so every forkful is a little stretchy, and the rest melts on top with Parmesan for a browned, savory crust.
- It’s built for busy nights. Everything is done in one pot and one skillet, and you can assemble it a day ahead.
Ingredients
You only need everyday pantry and fridge staples. Exact amounts are in the recipe card below.
For the meat sauce
- Lean ground beef: 90% lean keeps the sauce rich without a layer of grease. Mild Italian sausage, or half beef and half sausage, is also delicious.
- Onion, garlic and green bell pepper: the classic trio that gives the sauce sweetness and depth. Red bell pepper works too if you prefer it milder.
- Italian seasoning and salt: a dried herb blend of basil, oregano and thyme.
- Tomato paste: just two tablespoons, browned in the pan, makes jarred sauce taste slow-cooked.
- Marinara sauce: one 32-ounce jar. Pick one you’d happily eat on plain pasta.
- Diced tomatoes: a 14.5-ounce can with the juices, for texture and extra moisture.
For the casserole
- Spaghetti: one pound of regular or thin spaghetti. Whole wheat and protein pasta both work.
- Shredded mozzarella: about 6 ounces (1½ cups). Shred it from a block if you can, it melts smoother.
- Parmesan: ⅓ cup, finely shredded, for that salty browned top.
- Fresh parsley or basil: stirred in and sprinkled on top for freshness.
Equipment You’ll Need
- A large pasta pot and a colander
- A large, deep skillet or deep sauté pan for the sauce
- A 9×13-inch baking dish (ceramic or glass both work)
- A pair of pasta tongs to toss everything together
How to Make Baked Spaghetti Casserole
Step 1: Heat the oven and boil the pasta
Preheat the oven to 375°F (190°C) and lightly grease a 9×13 baking dish. Bring a big pot of well-salted water to a boil and cook the spaghetti for 2 minutes less than the package says. Drain it, and don’t rinse it. The starch on the surface helps the sauce cling.
Step 2: Brown the beef and vegetables
While the water heats, set a large skillet over medium-high heat. Add the ground beef, onion, green pepper and a pinch of salt. Break the meat into small crumbles and cook for 7 to 8 minutes, until the beef is browned and the vegetables are soft. Add the garlic and Italian seasoning and cook for 1 minute more, until fragrant. If there’s a lot of fat in the pan, spoon most of it off.
Step 3: Build the sauce
Push the meat to the sides, add the tomato paste to the center of the pan and let it sizzle for about a minute, until it darkens slightly. Stir it through the meat, then pour in the marinara and the diced tomatoes with their juices. Simmer for 8 to 10 minutes, stirring now and then. The sauce should look a little looser than a normal pasta sauce. If it’s thick, add a splash of water.
Step 4: Toss and assemble
Add the drained spaghetti to the skillet (or combine everything back in the pasta pot if your skillet is too small). Toss in half the parsley and about ½ cup of the mozzarella until every strand is coated. Tip it into the baking dish and spread it evenly, then scatter the remaining mozzarella and all the Parmesan on top.
Step 5: Bake and rest
Bake uncovered for 25 to 30 minutes, until the sauce is bubbling around the edges and the cheese is melted with golden spots. For a more browned top, switch on the broiler for the last 2 minutes and watch it closely. Let the casserole rest for 10 minutes before cutting, so the squares hold together, then finish with the rest of the parsley.
Tips for the Best Baked Spaghetti
- Salt the pasta water well. It’s the only chance to season the noodles themselves.
- Break the spaghetti in half if you like. It’s not traditional, but it makes the casserole easier to toss and to serve in neat squares, which kids especially love.
- Don’t skip the rest time. Cutting straight out of the oven makes the sauce run to the bottom of the dish.
- Taste the sauce before assembling. Jarred marinara varies a lot. A pinch of sugar tames sharp tomatoes, and a pinch of red pepper flakes wakes up a flat one.
- Use a deep dish. A shallow dish can bubble over, so set a sheet pan on the rack underneath if yours is full to the top.
Troubleshooting
My baked spaghetti came out dry. The pasta was probably fully cooked before baking, or the sauce was too thick. Next time, undercook the noodles and keep the sauce loose. For leftovers, add a spoonful of marinara or water before reheating.
It’s greasy on top. Use leaner beef, drain the pan after browning, and choose part-skim mozzarella.
The pasta is mushy. Pull the spaghetti a full 2 minutes early, and don’t let the finished casserole sit covered in a low oven for a long time.
Easy Variations
- Cheesy ricotta layer: spread half the spaghetti in the dish, dollop 1 cup of ricotta mixed with an egg over it, then add the rest of the pasta. It’s a lot like the filling in these spinach and ricotta stuffed shells.
- Homemade sauce: swap the marinara and tomatoes for about 5 cups of my homemade Bolognese sauce and skip browning the beef.
- Turkey or chicken: ground turkey is a lighter swap. Add an extra ½ teaspoon of Italian seasoning since it’s milder.
- Sneak in vegetables: stir in diced zucchini, sliced mushrooms or a couple of handfuls of baby spinach with the sauce.
- Vegetarian: replace the meat with a can of rinsed lentils or chopped mushrooms. For a veggie-packed pasta bake, try this roasted vegetable baked ziti.
- Spicy: use hot Italian sausage and add ½ teaspoon red pepper flakes.
What to Serve With Baked Spaghetti
Baked spaghetti is a full meal on its own, but a crisp side makes it feel complete. A simple green salad with a lemony vinaigrette, roasted broccoli or green beans, and a basket of garlic bread are my usual picks. Caesar salad is always a hit too. If you’re feeding a crowd and want a second hearty pasta on the table, a pot of classic American goulash pairs well and uses many of the same ingredients.
Make Ahead, Storage and Freezing
Can I make baked spaghetti ahead of time?
Yes. Assemble the casserole, let it cool, cover it tightly and refrigerate for up to 24 hours. Bake straight from the fridge, adding 10 to 15 minutes to the bake time, until hot in the center.
How long do leftovers last?
Store leftovers in an airtight container in the fridge for up to 4 days. Reheat single portions in the microwave with a splash of water, or warm the whole dish covered with foil at 350°F for about 20 minutes.
Can I freeze it?
Baked spaghetti freezes very well. Freeze the whole casserole (baked or unbaked) wrapped in plastic and foil, or freeze individual squares for easy lunches. It keeps for up to 3 months. Thaw overnight in the fridge before baking or reheating.
Baked Spaghetti vs. Baked Ziti: What’s the Difference?
They’re close cousins, but they eat differently. Baked ziti uses short tubes that trap sauce and ricotta inside, so every bite is a little pocket of filling. Baked spaghetti uses long strands that get tangled together with the meat sauce, which gives you a sliceable, almost lasagna-like square with crispy, cheesy edges. Baked spaghetti also tends to be quicker, since there’s no ricotta layer to mix and spread.
Another difference is how they handle leftovers. The long noodles in baked spaghetti hold together so well that a cold square can be pan-fried the next day in a little olive oil until the bottom turns crisp. It’s a favorite trick in my house, and it gives the leftovers a completely new texture.
A Few Words on Choosing Jarred Marinara
Since the sauce does most of the flavor work here, it’s worth a quick look at the label. Look for tomatoes listed first, olive oil rather than soybean oil, and no more than about 6 grams of sugar per half-cup serving. Sodium varies a lot between brands, from under 300 milligrams to over 600 per serving, so if you’re watching salt, compare a couple of jars and skip the extra salt in the recipe. A basic marinara is best; very herby or “garden vegetable” sauces can taste muddy after baking.
Scaling the Recipe
For a smaller household, halve everything and bake it in an 8×8-inch dish for 20 to 25 minutes. To feed a big crowd, double the recipe and use two 9×13 dishes rather than one very deep pan, which heats unevenly. Two dishes also means you can bake one tonight and freeze the other for a busy week.
Is Baked Spaghetti Casserole Healthy?
It’s comfort food, but it’s more balanced than you might expect. Each serving has about 27 grams of protein from the lean beef and cheese, plus vegetables from the sauce. To lighten it further, use whole wheat or chickpea pasta for extra fiber, choose part-skim mozzarella, and pick a lower-sodium marinara. Serving it with a big salad also makes a smaller portion feel like plenty.
Frequently Asked Questions
Should I cover baked spaghetti with foil?
Not for this recipe. Baking it uncovered lets the cheese brown and the top get a little crispy. If the top browns before the center is hot, for example when baking from cold, loosely cover it with foil for the first 15 minutes.
Can I use a different pasta shape?
Yes. Penne, rigatoni, ziti and linguine all work. Use the same weight of pasta and undercook it by 2 minutes.
How do I know when it’s done?
The sauce should bubble at the edges, the cheese should be fully melted with golden spots, and the center should be hot. An instant-read thermometer in the middle should read about 165°F.
Can I make it without meat?
Absolutely. Swap the beef for sautéed mushrooms, lentils or plant-based crumbles. The rest of the recipe stays the same.
Why add tomato paste if I’m using jarred sauce?
Frying a little tomato paste deepens the color and adds a savory, slow-cooked flavor that jarred marinara usually lacks. It’s the quickest upgrade you can make.
The Casserole That Disappears
This is the kind of dinner that gets requested again and again: cheesy on top, saucy in the middle, and ready with very little fuss. Make it once as written, then start playing with sausage, ricotta or extra vegetables. If you try it, leave a star rating and a comment below. I’d love to know how your family liked it, and don’t forget to save it to your Pinterest dinner board for next week.
Nutrition Information
Estimated nutrition per serving (1 of 8 servings):
| Nutrient | Amount |
|---|---|
| Calories | 450 kcal |
| Protein | 27 g |
| Carbohydrates | 53 g |
| Fat | 14 g |
| Saturated Fat | 6 g |
| Fiber | 4 g |
| Sugar | 7 g |
| Sodium | 740 mg |
Nutrition values are estimates calculated from standard ingredient data and will vary with the brands and exact amounts you use.
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Baked Spaghetti Casserole
Ingredients
Method
- Preheat the oven to 375°F (190°C) and grease a 9×13-inch baking dish.
- Boil the spaghetti in well-salted water for 2 minutes less than the package directions. Drain without rinsing.
- Meanwhile, brown the beef with the onion, bell pepper and a pinch of salt in a large skillet over medium-high heat, 7–8 minutes. Add the garlic and Italian seasoning and cook 1 minute. Spoon off excess fat.
- Stir in the tomato paste and cook 1 minute, then add the marinara and diced tomatoes. Simmer 8–10 minutes. Keep the sauce slightly loose, adding a splash of water if needed.
- Toss the spaghetti with the sauce, half the parsley and 1/2 cup of the mozzarella. Spread in the baking dish and top with the remaining mozzarella and the Parmesan.
- Bake uncovered 25–30 minutes, until bubbly and golden in spots. Broil 1–2 minutes for a browner top if you like.
- Rest 10 minutes, sprinkle with the remaining parsley, and cut into squares.
