This leftover spaghetti casserole recipe is an easy dinner meal made with leftover spaghetti noodles tossed in pasta sauce, then topped with cheese and baked until golden brown.
What to do With Leftover Spaghetti?
When I make spaghetti, there are always leftover noodles. And while I love a good pasta night, I’m not the biggest fan of plain spaghetti as leftovers. Instead, I turn those extra noodles into something even better—a cozy, cheesy Leftover Spaghetti Casserole for the next night’s dinner! In fact, this dish has become such a hit in my house that I now intentionally make extra spaghetti, just so I can whip this up later in the week.
And since I love making it a full meal, I like to serve it with a side of Bread Machine Italian Herb Bread or Garlic Bread —freshly baked, soft, and full of basil and oregano goodness.
So next time you have leftover spaghetti, don’t even think about tossing it—this casserole is calling your name! Looking for more of my favorite pasta recipes? Try my Beef and Ricotta-Stuffed Jumbo Shells next!
How long is leftover spaghetti good for?
When properly stored in a refrigerator, cooked spaghetti is good for up to 4 days. When you make spaghetti make sure to get your cooked leftover noodles in the refrigerator within 2 hours.
How To Make Spaghetti Casserole
If you have leftover pasta and sauce, you’re pretty much all set, but even if you don’t, it’s easy to cook up some noodles for this casserole.
Start by mixing leftover spaghetti noodles and pasta sauce with an egg, Italian seasoning, Parmesan cheese and ground beef or shredded chicken (note: meat is optional).
Place the spaghetti mixture into a baking dish and bake uncovered for 30 minutes.
After 30 minutes, remove from the oven and sprinkle mozzarella cheese and mushrooms on top and bake for an additional 10 minutes. And for those folks who don’t like mushrooms, skip them! We’re mushroom lovers in our house, so we always add them in!
Bake until cheese is melted and golden brown.
I hope you enjoy this Leftover Spaghetti Casserole!
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Leftover Spaghetti Casserole
PrintIngredients
- 8 ounces leftover spaghetti noodles
- 1 cup pasta sauce
- 1 egg beaten
- 1 teaspoon Italian seasoning
- 1/4 cup Parmesan cheese
- 1 cup cooked ground beef or shredded chicken OPTIONAL
- 1/2 cup mozzarella cheese
- 1/2 cup mushrooms chopped
Instructions
- Preheat oven to 350 degrees F.
- In a large bowl add spaghetti noodles, pasta sauce, egg, Italian seasoning and Parmesan cheese. Optional: Add in cooked ground beef or chicken if you are using it. Mix to fully combine all the ingredients.
- Pour the spaghetti mixture into a 9×9 baking dish and bake uncovered for 30 minutes.
- Remove from the oven and sprinkle mozzarella cheese and mushrooms on top and bake for an additional 10 minutes until cheese is melted.
Kelley says
Yum! This looks great! I love leftovers. We plan our menu around them. Ill have to try this this next time we have spaghetti!
Sophie says
I made this leftover spaghetti casserole & loved it so much, so did my husband Peter!
Chris @ Shared Appetite says
I’m so bad at using leftovers… my wife can’t stand it because she hates wasting food. Loving this idea of re-purposing leftovers into a casserole! Then it’s a brand new meal and boom… I’m excited again.
Davida @ The Healthy Maven says
I ate pasta last night! But with penne…don’t hate me!
Asmita says
Gorgeous! Loving this!
Laura @ Lauras Baking Talent says
I’m usually not into leftovers… so the hubby gets them in his lunch. I also don’t think I cook for an army 🙂 Either that or the hubby is an army…because we rarely have more than one lunch of leftovers.
Tiffany @ Triple Crème Decadence says
What a creative way to transform leftovers! I love how you added some mushrooms. Yum!
Norma | Allspice and Nutmeg says
You probably don’t know how much I love baked spaghetti. I love this and I will be making it.
Cindy @ Pick Fresh Foods says
For me there are some leftovers that I like and others that… ehhh, no thanks. I seem to always have leftover spaghetti, which I do love to have. This would be a great way to create a new meal from those leftovers. 😀
Alice says
I love getting creative with leftovers. There’s definitely that ‘cooking for a few’ mentality in our home, even though like you we’re just two! Will usually make Spag Bol jaffles in our home, but definitely need to give this casserole a whirl!
Christin@SpicySouthernKitchen says
Yum! Love the mushrooms on top! Love recipes that turn leftovers into something new 🙂
Koko says
Such an easy and quick dinner! Love this idea. Nothing like baked cheesy goodness….mmmm…
Consuelo @ Honey & Figs says
I love leftovers kmore than food itself, especially if it’s casseroles we’re talking about. This looks incredible my friend! When can I come over for dinner you said?
Chris @ The Café Sucré Farine says
This is a wonderful combination of ingredients Pamela. I can see why your husband loved it!
Carol at Wild Goose Tea says
Mmmm. I like leftover spaghetti as leftover spaghetti like you like the tacos. BUT cheese and mushrooms are not to be lightly considered! I might have to rethink my habit. Good redo recipe. Smiles—–
Cailee says
This looks delicious! So cheesy and yummy!! Also, what a great way to use up leftovers!! How creative!
Ashley says
I love leftovers! We actually almost always eat last night’s dinner for tomorrow’s lunch : ) Very few exceptions! haha What can I say, I hate having to worry about lunches! This leftover casserole looks awesome!
Juliana says
What a great way to use up the leftover…it sure looks great Pamela…
Have a wonderful week ahead 😀
Michelle says
Yum!! I have only tried making spaghetti pancakes (inspired by Giada) using leftover spaghetti. I usually make just enough for dinner that night. If there are leftovers, I re-create it into something else for lunch the next day. Like you were saying, the same exact thing twice in a row is not too much fun. :/
Nicole ~ Cooking for Keeps says
I’m a big leftovers gal, in fact, sometimes I make more than I can eat JUST so I can have leftovers. What I love even more than leftovers though? Turning them into something completely different!
vicky and ruth / May I Have That Recipe? says
Great use of those leftovers!
ela@GrayApron says
…nice to see all the happy kitties on top…
ela@GrayApron says
I’d go for that! 🙂 ela
Daniela @ FoodrecipesHQ says
In Italy we sometimes use leftover spaghetti to make a spaghetti frittata. Baking pasta is also another great option. Yum… pasta is too good to be tossed!
Shashi says
I used to think you were the muffin queen – now you can add leftovers queen to your expanding array of accomplishments!
I love leftovers (leftovers =No cooking on busy nights=score!!!)
Spaghetti in casserole form is a BRILLIANT concept, Pamela – simply BRILLIANT!
Monica says
I have learned to make extra these days so that I will have leftovers. This is a great idea – quick & easy, which is the best!
Suzanne says
Great way to use the leftovers, I am usually good for 1 day of leftovers then it just gets too old but this breathes new life into the leftover spaghetti. I too tend to cook for an army and its just me and the pugs, I need to learn how to downsize my meals.
Amanda @ Once Upon a Recipe says
Repurposing leftovers is my favorite way to make an old meal taste new! Love the sounds of this casserole!
marcie says
There are some leftovers that I look forward to every night too. This spaghetti would be one of them — anything with melted cheese all over the top is something I’d enjoy night after night!
Angie@Angie's Recipes says
I love leftovers! This is a delicious use of leftover chicken and pasta. The casserole looks comforting and delicious. A perfect weekday meal.