Baked Spaghetti with Cream of Mushroom Soup

It took me until adulthood to finally discover the joy of mushrooms. What I once thought of as a slimy, chewy vegetable turned out to be so much more: earthy, umami-rich and wonderfully tender when cooked just right. Now, I look to add mushrooms to all my favorite cozy, savory dinners—like this baked spaghetti with cream of mushroom soup.

Mushrooms (and lots of cheese) transform this typical pasta dinner. While the dish does require a bit of prep for the different layers, the yield is plentiful, so you’ll be ready to go for a dinner party or for weeknight leftovers. Serve this comforting main alongside baked Parmesan broccoli or a simple chopped salad, since it’s all about balance.

Baked Spaghetti with Cream of Mushroom Soup Ingredients

• Onion: Use a yellow or sweet onion here. It’ll add sweetness and savoriness. Even a shallot would work beautifully. Red onions are too strong for this dish.
• Green pepper: Green peppers are a little bitter and a little crunchy, and they add a pop of color and a bit of balance. Cut the bell pepper the right way to avoid any waste.
• Diced tomatoes: The tomatoes cook down and provide moisture and acidity, harmonizing well with the other ingredients. You’ll want the entire 28-ounce can here, liquid and all.
• Mushroom stems and pieces: These will be canned. If you prefer fresh, look for mushroom varieties like cremini, button or shiitake. If you use shiitakes, remove the woody stems.
• Ripe olives: The briny olives cut through some of the creaminess and add an additional umami element. Black olives work beautifully here, but you can use fresh Castelvetrano olives for a buttery flavor.
• Dried oregano: Oregano, a staple in many pasta sauces, is aromatic and herbal, and provides depth to the dish.
• Ground beef: While this is optional, beef adds a savory heartiness and extra protein. Make sure to cook the beef and drain the liquids before adding it to the sauce.
• Spaghetti: Cook your spaghetti before starting this recipe. Once it’s done, toss it in 1 or 2 teaspoons of olive oil to prevent the noodles from sticking to one another as they sit.
• Cheddar cheese: I always like to shred my cheese fresh from the block for the freshest flavor. If you’re going the bagged shredded route, spring for the best shredded cheddar cheese.
• Condensed cream of mushroom soup: You can use any brand you prefer. This adds instant creaminess with minimal effort. Score!
• Parmesan cheese: Sprinkle Parmesan on top before baking the casserole. I love the added complexity that this salty, nutty topping brings.

Directions

Step 1: Prepare the sauce

Preheat your oven to 350°F. In a large skillet, saute the onion and green pepper in the butter until tender. Add the tomatoes, mushrooms, olives, oregano and, if desired, the ground beef. Simmer them, uncovered, for 10 minutes.

Step 2: Layer the pasta, sauce and cheese

Place half of the spaghetti in a greased 13×9-inch baking dish. Layer this with half of the vegetable mixture and 1 cup of the cheddar cheese. Repeat this step to make layers.

Step 3: Bake the casserole

In a small bowl, combine the mushroom soup and water until they’re smooth, then pour the mixture over the casserole. Sprinkle the casserole with the Parmesan cheese. Bake it, uncovered, until it’s heated through, about 30 to 35 minutes. Let it cool for a few minutes at room temperature, then serve it.

Baked Spaghetti with Cream of Mushroom Soup Variations

• Use other meats: If you aren’t feeling beef, you could sub in ground chicken or ground turkey. You can also use Italian sausage in place of, or in addition to, the beef.
• Mix up your noodles: Other pasta shapes will work in this recipe. We recommend a long noodle, such as fettuccine, bucatini, mafalda or linguine.
• Add veggies: Sneak chopped broccoli, sauteed spinach, shredded carrots, sauteed zucchini or chopped cauliflower into your vegetable mix for some extra nutrients.

How to Store Baked Spaghetti with Cream of Mushroom Soup

Allow the baked spaghetti with cream of mushroom soup to cool completely to room temperature, then store it in an airtight container in the fridge for up to four days. Reheat portions in a saucepan on the stove, or gently in the microwave.

Can you freeze baked spaghetti with cream of mushroom soup?

Yes, you can freeze baked spaghetti with cream of mushroom soup. Once it’s baked, allow everything to cool to room temperature, and make sure to do so in less than two hours so the food doesn’t enter the temperature danger zone. Cover the pan with storage wrap and foil, or transfer leftovers to a freezer-safe airtight container. Freeze the baked spaghetti for up to three months, then thaw it overnight in the fridge before reheating it.

Baked Spaghetti with Cream of Mushroom Soup Tips

How can I keep my pasta from sticking while cooking?

To keep your pasta from sticking while cooking, stir it every minute or so. If you don’t stir while cooking, the pasta will cook together in big clumps. After you drain the pasta, toss in 1 or 2 teaspoons of olive oil and stir the noodles to coat them. The olive oil prevents them from sticking as they sit and wait for their moment to be layered in the dish.

Can I make this in an 8×8-inch dish?

Yes, you can bake this in an 8×8-inch dish if you want to make a smaller portion. Cut your ingredients in half, and cook, assemble and bake everything according to the recipe. You can also cook the recipe in two 8×8-inch dishes, and freeze one for later.

Can I make baked spaghetti with cream of mushroom soup gluten free?

Yes, you can make baked spaghetti with cream of mushroom soup gluten free. An easy swap is using gluten-free spaghetti. You’ll also need to make sure your cream of mushroom soup is gluten free, since some brands may contain flour. Double-check all other packaged goods to ensure they’re gluten free, too.