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.
BF says
What’s the purpose of adding the egg? I wanted to make this for dinner tonight with leftover noodles and pasta sauce with ground venison already mixed in
Pamela Reed says
The egg acts like a binder in the casserole, holding the pasta noodles together.
kim says
okay! i sauteed mushrooms and onions and garlic and fresh spinach. added that and rice to leftover spaghetti and meatballs. used that pinwheel masher tool to spread out meatballs. added beaten egg and cheese. OMG! so freakin delishous!
kim says
for the first time in my life i DID NOT make too many spaghetti noodles. rather than make more noodles i think im going to try that 1 minute microwave rice. i will let y’all know how it works out. my husband loves rice so its not a huge issue.
Donna Singletary says
This recipe was very good. I had leftover spaghetti with meat sauce. I followed the recipe except I mixed all ingredients together and poured into a two quart dish. At 20 minutes, sprinkled more mozzarella cheese to melt. Dish was done in 25 minutes.
Marie.D says
Loved it!! My granddaughter made homemade spaghetti for Christmas dinner and I used this recipe to use the leftover spaghetti! It was a hit with my husband, mother-in-law and myself!! Will definitely make again!
Nicole Willard says
Great recipe! Thanks!
Pamela Reed says
Happy to hear you liked it Nicole! 🙂
Jane says
Why do you add an egg?
Sharon K Smith says
I am Desperate to get baked spaghetti recipe .sooner HELP .E please
Pamela says
Hey Sharon, the recipe is listed in the recipe card. Let me know if you can’t see it.
Ginny Felker says
Great recipe! Any suggestions for an egg allergy as a substitute? Thank you!
MichaelK says
I kept it very simple, added just the tomato sauce, egg, and parmesan to the leftover pasta. I did cover it for about half the baking time. Uncovered then added the mozzarella and baked 15-20 minutes more. It went together easily and tasted great. Thanks for sharing!
Kish says
Loved the recipe.. What about adding cooked shrimp?
Pamela says
That would be delicious too!
Olivia hill says
Loved it but time and temperature were confusing 360? 10 or 30 mins?
Pamela says
Hi Olivia. The temperature is 350 degrees F, not sure where you’re getting the 360 at? You bake for 30 minutes, and then add cheese and bake for 10 minutes more, so 40 minutes total. Hope that helps.
Patti says
Forgot to rate it! My husband loved it!
Patti says
Great way to jazz up leftover spaghetti. Yummy!
Christina J says
Thank you for turning leftover spaghetti night into a much more enjoyable experience. My husband and kids always complain on leftover night, but this had them asking for seconds! We added breadcrumbs per your suggestion and loved it!
Suzanna says
When do you add the sauce?
Pamela says
Hey Suzanna, mix leftover spaghetti noodles and pasta sauce with egg, Italian seasoning, Parmesan cheese and shredded chicken (optional). Hope this helps – enjoy!
Marissa says
I use this recipe every time we have leftover spaghetti. It is delicious, simple, and affordable. On another note, the website should be ashamed. I had to try 6 times to see the recipe because the pop ups redirected even if you hit the close button.
Pamela says
Hey Marissa, if there’s a specific ad that you see that won’t close, can you please email me a screenshot so I can take care of it? I’m always looking for ways to better improve readers experience! Glad you enjoy this Casserole recipe!
Dawn Derson says
My Mother made way too much of her famous spaghetti,like two pounds too much! So I googled a quick recipe to see if I absolutely had to use egg,and I decided to after reading most of the recipes with a basic ingredient list called for it.
It was so yummy! I used mozzarella, Parmesan, sharp cheddar,and a little Gouda. I had to combine all my cheeses to have enough to cover the mixture. I put olive oil soaked plum tomatoes on top. Even though my toppings were almost weird, the taste of the filling was great! Lol I loved your presentation in the blue. Leftovers are my favorite!
Pamela says
That sounds so delicious Dawn! I love the addition of the olive oil soaked plum tomatoes, I’ll need to try that once our tomatoes are ready to be picked!
Karen @ Kama Fitness says
Look at that cheese….omg…..yum.