This Italian Inspired Sausage & Spaghetti Squash Casserole is a Family Favorite
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This Italian sausage and spaghetti squash casserole needs to be added to your dinner rotation.
My Italian grandmother, known as Ma, was an incredible cook.
She was always fussing over a hot stove. My heart sang for dinner at Ma’s house, whether it was sausage with peppers, slow-cooked pork in hearty ragu, or eggplant parmesan with a side of pesto linguine. Anytime I have an opportunity to create an Italian dish, I’m inspired by her garlic-lovin’ roots and freestyle cooking which always turned out amazing.
This Italian sausage & spaghetti squash casserole is pretty basic, however, the taste is rich, hearty, and classic. I think Ma would approve.
Oh, and did I mention the kiddos love it, too?
I never thought my son would devour squash by the handful! The cooking process is simple but the presentation and flavors are pretty extraordinary… My low-carb bestie is spaghetti squash, and the whole family loves it! I don’t miss noodles at all with this spaghetti squash casserole recipe.
Italian Sausage & Spaghetti Squash Casserole
yield: 12 SERVINGS
prep time: 30 MINUTES
cook time: 1 HOUR 10 MINUTES
total time: 1 HOUR 40 MINUTES
The cooking process is simple, but the presentation and flavors are pretty extraordinary.
- 1 medium spaghetti squash, about 3 to 3 1/2 lbs whole (approx 5 cups cooked)
- 1 1/2 pounds ground Italian sausage
- 1/2 cup onion, finely diced
- 1/2 cup orange or red bell pepper, finely diced
- 3 cloves garlic, minced
- 24 oz jar no-sugar-added pasta sauce (or use your favorite homemade sauce)
- 1 egg, beaten
- 1/2 cup grated Parmesan cheese
- 4 cups shredded mozzarella cheese, divided
- 1/2 teaspoon onion powder
- 1/2 teaspoon garlic powder
- 1/2 teaspoon salt
- 1/2 teaspoon black pepper
- fresh parsley, chopped, as optional topping
This casserole will require a 9x13 inch casserole dish (you may prep it with non-stick cooking spray if desired for easier cleanup).
Preheat the oven to 400 degrees. Line a baking sheet with parchment paper or tinfoil. Halve the squash (lengthwise or widthwise) and scoop out the seeds. Sprinkle the halves with a bit of salt. Place squash halves cut side down on a baking sheet.
Bake squash in preheated oven for about 35 to 40 minutes or until easily pierced with a knife. Remove from oven and cool until able to easily handle. Use a fork to scrape out the "spaghetti" into a mixing bowl.
Reduce oven temperature to 375 degrees in preparation for the casserole.
To the squash, add egg, Parmesan cheese, onion powder, garlic powder, salt, and black pepper. Mix well. Set aside.
In a large saucepan, over medium to medium-high heat, brown the Italian sausage until just done. Do not drain. Add the onion, bell pepper, and garlic. Cook for another 3 to 5 minutes until the onions become translucent.
Remove from heat. Add the 24 oz jar of pasta sauce. Mix thoroughly. Set aside.
Grab your casserole dish and begin layering.
First, add about 2/3 cup of meat sauce to the bottom of the dish, and spread evenly. Next, layer half the spaghetti squash mixture on top of the meat sauce using a fork to evenly press it into a uniform thickness, almost as if it's acting as a lasagna noodle.
Top the squash layer with half of the remaining meat sauce, and spread evenly. Sprinkle 2 cups of the shredded mozzarella cheese over the meat sauce.
Spread the remaining squash mixture using the same technique as above, followed by the rest of the meat sauce. Sprinkle the last 2 cups of mozzarella cheese evenly over the meat layer.
Bake in preheated, 375 degree oven until cheese is bubbly and golden brown, about 25-30 minutes.
Let cool for at least 10 minutes. This allows the casserole to be set up so that each serving comes out clean and beautiful. Enjoy!
Yield: 12 servings, Serving Size: 1 cup
Amount Per Serving: 351 Calories | 25.5g Fat | 11g Total Carbs | 2.4g Fiber | 5.2g Sugar | 20.2g Protein | 8.6g Net Carbs
A few tips when making this Italian spaghetti squash casserole:
- This recipe starts with cooking the spaghetti squash. Check out our helpful post on how to cook spaghetti squash perfectly every time. You can even cook it in an air fryer to save on time!
- When layering the squash, I use a fork to smooth it out as evenly and as flat as possible. I feel this method creates a nice density that truly replaces the need for a noodle.
- For this casserole, I used Ragu Simply Traditional Pasta Sauce. It’s sugar-free and made with 100% olive oil. I was surprised at how much I liked it with the Italian sausage mixture. I definitely recommend it for a quick, easy, and affordable option. Another great option is Rao’s Marinara Sauce.
This spaghetti squash casserole is a game-changer!
This dish is seriously so delicious! If someone in your life is hesitant about trying a keto dish or spaghetti squash in general, make them this spaghetti squash casserole. I guarantee it will win them over!
This would also be great to bring to some sort of gathering or potluck. There might be some fighting for seconds, though.
Here’s what my Hip sidekick Emily had to say about this casserole:
“Anything that has marinara sauce and lots of cheese is a win in my book! I love spaghetti squash as well and it’s so good in this casserole! This was a big hit in my house and I’ll definitely be making it again!”
My sis Collin also loves this recipe! Here’s what she had to say:
“Oh my… this is one of my favorite go-to Italian recipes! If you miss pasta night, this recipe will have you no longer missing it again. This casserole totally hits the spot. It’s so flavorful too, and the leftovers are SO good! Make it – you won’t regret it!” – Collin
I appreciate your tip about using Ragu Traditional Pasta Sauce for this recipe. My family loves anything pasta/tomato-based! However, finding sugar-free pasta sauces has been a challenge. I can’t wait to purchase Ragu’s sugarfree sauce and to test out this recipe :).
Susan, you betcha! And for variety, I also like Newman’s Own pasta sauces. Like Ragu’s Simply line, Newman’s Own is also free of added sugar. Woot, woot!
I had this tonight. It was awesome! My husband didn’t even know about the squash!
Yay for sneaky squash! 😉
This is the BOMB!!! My son didn’t even notice it was spaghetti squash. This is definitely a must in my rotation!!
Yay! SO glad this was a hit! Thanks a ton for the feedback, Jennifer!
Could you substitute butternut squash?
Hi there Alexandra. Great question! I avoid winter squash on keto as it is much higher in carbs compared to zucchini, yellow (summer) squash, spaghetti squash, and pumpkin. For reference, spaghetti squash is only 5.5 net carbs per cup while butternut squash is a mountainous 13 net carbs per cup. Hope that’s helpful information!
I made this tonight for my family. It was so delicious! I tweaked it and made it my own, but oh yes….this was a super great idea for a dinner meal. Couple of little things I did, first I used a roll of breakfast sausage because that’s what I had on hand. I cooked the sausage, one yellow pepper, half a medium onion and garlic powder all together. While that was cooking, I put my spaghetti squash in the insta pot for 8 minutes. The meat and squash were done about the same time so I started my layering. I did use 8oz of cottage cheese with an egg mixed in as one of my layers. I layered mine more like a lasagna style. Squash, meat sauce mixture, cottage cheese mixture, cheese, repeat. So thank you so much for this recipe idea!! My non veggie eating nephew had two servings! We loved it!
Hi Kitty. I’m so glad you enjoyed it. Sounds like your customizations were a hit—Well done!
Could you cut down cooking time by using an instant pot?
Certainly, Jennifer. You would just need to adjust the cooking time as the IP cooks much faster. Hope that helps!
OMG Marley!!!!!! I had to leave a review for you after making this. I made this over the weekend, and have eaten it everyday for lunch and dinner!! Its sooo delicious. I substituted the Italian sausage with beef breakfast sausage. I did need to drain a little of the fat off before adding the sauce, but my end results turned out perfect! I also made a salad to complement it. Boom! I will be making this again for sure. **The spaghetti squash is a hidden gem. Thanks so much for this!! Be blessed!
Aww, Thanks so much for the sweet comment and feedback! I’ll be sure to pass this along! 💕 We’re super glad you enjoyed it!
This is absolutely delicious! We’ve made it at least 6 times, maybe more. Our teenagers and company who ate it loved it too. Put into our normal rotation for sure!
Yay! SO glad to hear how yummy it was! Happy you can add it to your regular line up!
I enjoyed this recipe! I totally forgot to add the egg and I used Paul Newman Tomato and Basil sauce. I’ll definitely make it again. I’m not on the keto diet, just looking for something new to do with spaghetti squash, but I am no longer a pasta eater. This was perfect! Thank you!
Even if you are not keto, this is a great one to enjoy!
That looks delicious!
Hope you love it if you decide to try it! 💕
This was so delicious! I’m trying to cut down on carbs and my husband wanted spaghetti. This was delicious and we both enjoyed it and decided wee will be making it more often. We have plenty of home made tomato sauce we canned last summer. We are planning on expanding our garden to have more! We even saved the seeds from the spaghetti squash so we can try growing them this summer.
SO glad you both enjoyed it, Donna! 🙌🎉 Happy you’ll be able to add it to your regular rotation. Thanks a ton for commenting! 🥰
Can you subsitite zoodles or thinly sliced cabbage? Or even shredded slaw cabbage?
Hi there! 🤗 We haven’t tried that. However we’re thinking that should work well! You can cut the bake time in half for the zoodles, including the part in step 9 when you melt the cheese. Zoodles tend to be watery too. Prior to adding to a casserole, you would want to place them in colander, add a sprinkle of salt, and let sit for 10 minutes or so, then dry with paper towels to help remove the extra water. Let us know how it turns out if you do make that substitution. Here are some other recipes that may also be helpful! 💕💕