Spaghetti Squash Meatball Casserole
This Spaghetti Squash Meatball Casserole offers a healthy and satisfying alternative to the timeless Italian dish. Featuring layers of ‘al dente’ spaghetti squash, savory meatballs, marinara sauce, and melted mozzarella, it’s the perfect kid-friendly, low-carb family dinner! *Sponsored by Newman’s Own.
When I think of spaghetti and meatballs, childhood comfort food instantly comes to mind. It was one of my fave meals as a kid –right after my mom’s barbecue ribs smothered in her signature Homemade BBQ Sauce, of course.
Although I don’t indulge in traditional pasta much these days, when I do crave noodles, I opt for higher-protein varieties like lentil, quinoa, or edamame pasta. Lately, however, I’ve been all about spaghetti squash!
This veggie is a fantastic substitute for pasta, offering a similar al dente texture without the extra carbs or calories. That said, if you’re new to spaghetti squash “noodles,” this healthy baked spaghetti and meatballs casserole is the perfect introduction. Let’s get right into it!
Why you’ll love this recipe
This casserole with spaghetti squash and meatballs offers the perfect balance of semi-homemade convenience and made-from-scratch satisfaction. Featuring Newman’s Own marinara sauce and homemade Italian meatballs, it captures traditional spaghetti and meatballs’ irresistible flavors and textures in a meal that won’t leave you feeling weighed down.
With its wholesome spaghetti squash base, protein-packed DELICIOUS meatballs, and other nutrient-rich ingredients, this casserole is an excellent option for those watching their carbs. But it’s also the type of healthy meal that everyone –and I mean even the pickiest eaters– will LOVE! Give it a try, and your taste buds (and your family!) will thank you!
Ingredients you’ll need
- Spaghetti squash. Our baked meatball casserole’s starring squash! Select a large one with dull skin that feels heavy for its size, indicating it will yield lots of “noodles.”
- Extra virgin olive oil. For roasting the squash, browning the meatballs, and sautéing the onion and garlic.
- Lean ground beef. I prefer 90% or less for juicy, flavorful meatballs. You can substitute ground turkey, chicken, or plant-based ground meat for a leaner or vegetarian option.
- Whole egg and egg white. These help bind the meatballs together and keep them moist. Yes, you need both!
- Garlic cloves. Adds robust flavor to both the meatballs and the squash. You can substitute each clove with 1/4 teaspoon of garlic powder if needed.
- Dried parsley. Gives the meatballs a subtle herbal note. If you don’t have dried parsley, fresh parsley works just as well.
- Parmesan cheese. Freshly grated. Adds a rich, cheesy flavor to the squash mixture.
- Breadcrumbs. Help bind the meatball mixture. I used gluten-free breadcrumbs, but regular breadcrumbs work just as well if you’re not gluten-sensitive.
- Onion. I used sweet onion, but yellow or white onions are suitable substitutes if that’s what you have on hand.
- Italian seasoning. Select a store-bought blend to give your casserole that classic Italian flavor. Or, make your own with a mix of dried oregano, basil, rosemary, and thyme. Fresh basil is also amazing here!
- Marinara sauce. Newman’s Own marinara is my go-to, but you can use any hearty red sauce. Try my Marinara Sauce or San Marzano Pizza Sauce for a homemade touch.
- Fresh mozzarella cheese. Sliced. Adds a creamy, melty topping. You can use mozzarella shredded directly from a block of low-moisture mozzarella instead of slices.
- Salt and pepper. Essential for seasoning.
Time-saving shortcut
This casserole features Newman’s Own Organics Marinara Sauce, which I absolutely adore for creating quick, nutritious meals. Their sauces are not only delicious but also made without any added sugar! Check out their website for a full selection of their tasty organic pasta sauces.
How to make baked meatball casserole with spaghetti squash
Step 1: Bake the spaghetti squash. Slice the spaghetti squash lengthwise and brush the insides with olive oil. Place the squash cut-side down on a cookie sheet and bake at 350°F until tender (35-40 minutes).
Step 2: Form the meatballs. Mix all the meatball ingredients (except the olive oil) in a large bowl using your hands. Shape the mixture into 18-20 golf ball-sized meatballs and place them in the fridge until the squash is ready.
Step 3: Brown the meatballs. Once the squash is done, flip it cut-side up and let it cool a bit. Increase the oven temperature to 375°F. Meanwhile, heat olive oil in a large skillet over medium-high heat and brown the meatballs on all sides,
Step 4: Bake the meatballs. Transfer the browned meatballs to a baking sheet and bake at 375°F until cooked through (about 20 minutes).
Step 5: Sauté the aromatics. While the meatballs are baking, wipe out the skillet, heat more olive oil over medium heat, and sauté the onion and garlic until soft and fragrant.
Step 6: Create “noodles” and combine. Scoop out the seeds and shred the flesh from the squash with a fork. Add the shredded squash, Parmesan cheese, Italian seasoning, salt, and pepper to the skillet and stir well. Remove from the heat.
Step 7: Assemble the casserole. Spread a thin layer of sauce on the bottom of a 9×13-inch baking dish. Spread the squash mixture on top, then arrange the meatballs over the squash. Pour the remaining sauce over everything and top with fresh mozzarella slices.
Step 8: Bake and serve. Lower the oven temperature to 350°F and bake the casserole for 30 minutes.
Recipe tips and FAQs
- To safely cut the squash, stabilize it on a non-slip cutting board and use a sharp chef’s knife. Cutting the squash lengthwise can be challenging, so start by cutting off the stem to create a flat base.
- Use a fork to shred the roasted squash into “noodles.” Wait until the squash has cooled slightly to make handling it easier.
- After shredding the squash, drain any excess moisture from the squash to prevent the casserole from becoming too watery.
- If the squash is too hard to cut, pop it in the microwave for a few minutes to soften it slightly before cutting.
- Avoid overworking the meat when mixing the meatball ingredients, as this can make the meatballs tough. Mix until just combined.
- Chill the meatballs in the refrigerator before baking to help prevent them from falling apart during browning/baking.
- Allow the casserole to cool for a few minutes before serving. This helps the flavors meld and makes it easier to slice and serve.
Variations
- Switch up the meatballs – Swap the beef meatballs for turkey, chicken, or bison. These options are just as flavorful and pack in plenty of protein.
- Extra cheesy – For a more decadent, creamy dish, mix ricotta cheese or a blend of Italian cheeses into the squash mixture before assembling the casserole.
- Keto meatball casserole – This recipe is already low carb as a meatball casserole without pasta. By replacing the breadcrumbs in the meatballs with almond flour or crushed pork rinds, you can cut out more carbs while still holding the meatballs together.
FAQs
Yes! To make this casserole dairy-free, use a dairy-free mozzarella alternative and replace the Parmesan cheese with a dairy-free option such as nutritional yeast. You’ll still get a cheesy flavor without the dairy.
This recipe is naturally gluten-free if you use gluten-free breadcrumbs for the meatballs and verify that your marinara sauce is gluten-free. Newman’s Own Organics Marinara Sauce is a great gluten-free option!
You can prep, brown, and bake the meatballs, roast the spaghetti squash, and assemble the casserole up to a day in advance. Cover it tightly and refrigerate it. When you’re ready to serve, simply bake it as directed, adding a few extra minutes to the baking time if needed.
Serving suggestions
This spaghetti squash meatball casserole is a great way to satisfy those comfort food cravings and get in a healthy serving of veggies, too! You can pair the meal with a crisp Caesar or copycat Olive Garden salad. Don’t forget a slice of garlic bread or gluten-free breadsticks to sop up the sauce!
Storing & freezing
Storing: Store any leftover spaghetti squash and meatball casserole in an airtight container in the refrigerator for 3-4 days. To reheat, bake at 350°F until warmed through, or microwave individual portions for 1-2 minutes.
Freezing: This casserole also freezes well! After baking, let it cool completely, then cover it tightly with plastic wrap and aluminum foil. Freeze for up to 2 months. To reheat, thaw in the refrigerator overnight and bake at 350°F until heated through.
More squash recipes
- Cauliflower Squash Casserole
- Savory Stuffed Pattypan Squash
- Stuffed Air Fryer Acorn Squash
- Butternut Squash Chicken Casserole
If you love this healthy baked spaghetti and meatballs casserole recipe, I would be so grateful if you could leave a 5-star 🌟 rating in the recipe card below. I love reading your comments and feedback!
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Spaghetti Squash Meatball Casserole
Ingredients
- For the meatballs:
- 2 lbs lean ground beef 90% or less
- 1 whole egg
- 1 egg white
- 2 cloves garlic minced
- 1 tbsp dried parsley
- 1/2 cup grated parmesan cheese
- 1/2 cup breadcrumbs -I use gluten free
- 1 tbsp extra virgin olive oil
- salt and pepper to taste
- For the casserole:
- 1 large spaghetti squash
- 2 tbsp extra virgin olive oil
- 4 cloves garlic minced
- 1 sweet onion chopped
- 1 tbsp Italian seasoning -fresh basil is great here, too
- 1/2 cup parmesan cheese
- 1 23.5 oz jar Newman’s Own marinara sauce or your favorite thick Marinara sauce
- 8 oz fresh mozzarella cheese sliced (I like to use a blend of buffalo mozzarella and shredded)
Instructions
- Preheat oven to 350 degrees F.
- Slice spaghetti squash down the middle, lengthwise and brush the inside part with olive oil.
- Lay squash, seeded part down onto a cookie sheet and bake for 35-40 minutes.
- While squash is baking, mix all meatball ingredients together (except olive oil) in a large bowl, working it well with your hands.
- Roll into golf ball size balls and refrigerate until your squash comes out of the oven. You should have about 24 meatballs.
- When squash is done, flip it with the flesh side up and set aside to cool
- Turn oven up to 375 degrees F. and heat 1 tbsp olive oil a large skillet over medium-high heat.
- Brown meatballs on all sides and place them onto a baking sheet.
- Bake meatballs for 20 minutes, until cooked through.
- Wipe out your skillet and add the remaining tbsp olive oil.
- Cook onion and garlic on medium heat until onion is soft, about 4-5 minutes.
- while onion and garlic are cooking, spoon out the seeds in the squash and shred squash with a fork (it should look like thin noodles)
- Add shredded squash to skillet, along with parmesan cheese, Italian seasoning and salt and pepper, to taste.
- Stir until just blended and remove from heat.
- Spread a thin layer of sauce in the bottom of a 9×13 baking dish
- Top with squash mixture, then arrange your meatballs on top
- Pour remaining sauce over and top with slices of fresh mozzarella.
- Lower oven heat to 350 degrees and bake for 30 minutes.
- Serve immediately.
Notes
- After shredding the squash, drain any excess moisture from the squash to prevent the casserole from becoming too watery.
- Prep in advance, to save time, make the meatballs and bake the squash a day in advance.
- Avoid overworking the meat when mixing the meatball ingredients, as this can make the meatballs tough. Mix until just combined.
- Chill the meatballs in the refrigerator before baking to help prevent them from falling apart during browning/baking.
- Allow the casserole to cool for a few minutes before serving. This helps the flavors meld and makes it easier to slice and serve.
Nutrition
*This post has been updated with helpful tips and new photos. This is the original baked casserole image from 2017. I decided to use a blend of buffalo and shredded mozzarella in the new version for a cheesier top layer. Both versions are delicious!
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My kids will be in heaven with this. Making tomorrow night with the squash that’s been on the counter!
Let me know how you all like it Serena!:)
Thank you Serena! Spaghetti squash is one of my favorite pasta subs!
I made this for dinner last Wednesday and it was delicious! Iโm pretty sure itโs my new favorite way to eat spaghetti squash! ๐
This was amazing! My husband raved about and asked me to make it again two days later ๐
Quick and Easy Family Recipes
I’m so glad that you enjoyed it!!