This Spaghetti Squash Casserole made with spaghetti squash, sausage, and marinara sauce, is not only a gluten-free, low carb, and Paleo casserole, it is a satisfying, delicious, hearty yet healthy recipe that you entire family will enjoy–even if they aren’t on any special diet.
Spaghetti Squash Casserole is delicious served with a Spinach Avocado Salad and if you aren’t watching your carbs, add a side of Garlic Toast as well.
Spaghetti Squash Casserole
I have always loved spaghetti squash. As a child, I remember eating it as a side dish slathered in butter and salt and pepper.
Recently, I have been using spaghetti squash as more of the star of the show! It t is an easy vegetable to use in place of carbs, like noodles. But even if you aren’t low carb, using spaghetti squash in place of noodles is a great incorporate more veggies into your diet.
When paired with spicy Italian Sausage, and flavorful marinara sauce, spaghetti squash becomes the base for a delicious, flavorful casserole–that happens to be gluten-free, low-carb, dairy-free, and Paleo friendly as well.
And while this spaghetti squash casserole is a great dish to accommodate so many special diets, bottom line is that this simple casserole is comforting, hearty, and full of incredibly flavor. Not to mention EASY! This casserole is made with only 5 key ingredients!
Notes/Modification on Ingredients
- Sausage: Use ground Italian sausage. Pork, chicken, or turkey all work well in this casserole. Just be sure to read the ingredients in your sausage as some brands have added gluten or sugar–which is a no-no for many people following a low carb or paleo lifestyle. And gluten is certainly a no-no for anyone that is gluten-free!
- Garlic and Onion: Aren’t most recipes improved with the addition of garlic and onions?! Glad you agree!
- Oregano: I keep this super simple and just add in dried oregano. The spaghetti sauce is already flavored, so just a bit of dried oregano really makes this dish pop.
- Spaghetti sauce–Use my homemade spaghetti sauce, Instant Pot Spaghetti Sauce, or your favorite jarred sauce. Be sure to omit sugar from homemade sauce or use no added sugar sauce to keep this Paleo Friendly.
- Eggs: Eggs will help to bind this casserole together and add an additional dose of protein.
- Spaghetti squash: Of course we need spaghetti squash, as it is the star of this casserole. Select a large spaghetti squash that is free from bruises and blemishes and feels slightly heavier than it looks.
- Cheese: Cheese is COMPLETELY optional, but if you are not dairy-free or following a paleo diet, I strongly suggest adding a layer of Mozzarella and Parmesan cheese to the top of this casserole.
How to make Spaghetti Squash Casserole
Step One: Prepare Spaghetti Squash
I prefer preparing Instant Pot Spaghetti Squash as the base for this casserole. But if you don’t have an Instant Pot, follow the following steps to roast your squash.
- Start by cutting the squash in half and scooping out the seeds.
- Place squash face down on baking sheet.
- Roast the squash for 35 minutes at 400 degrees.
- Once squash is finished cooking and cool enough to handle, scoop out strands of squash and place in large bowl.
Step Two: Prepare Casserole
- While the squash is cooking, brown the sausage and onions together until the sausage is cooked through.
- Add in garlic and oregano and cook for 1-2 minutes longer.
- Drain off any excess grease.
- Add meat mixture to spaghetti squash.
- Add in whisked eggs, 2 cups of the tomato sauce, and season with salt and pepper, Mix well.
- Transfer mixture to a greased 8×8 dish.
- Top with an additional cup of spaghetti sauce.
- Bake for 1 hour or until top is bubbly and browned.
- Serve!
More Allergy Friendly Dinner Recipes
- Paleo Veggie Burgers
- Crock Pot Pork and Sauerkraut
- Skillet Pork Tenderloin
- Gluten Free Eggplant Parmesan
Spaghetti Squash Casserole
Ingredients
- 1 large spaghetti squash
- 1 tablespoon olive oil
- 1 pound Italian sausage
- 3 eggs
- 3 cups spaghetti sauce
- 1 teaspoon dried oregano
- 1 onion minced
- 3 cloves garlic minced
Instructions
Prepare Spaghetti Squash
- Preheat oven to 400 degrees.
- Cut the squash in half and scoop out the seeds. Place cut side down on a baking sheet that has been lightly greased with olive oil and roast for 35 minutes. After squash is baked, reduce oven heat to 350 degrees.
- Once cool enough to handle, remove strands of spaghetti squash and place in large bowl.
Prepare Casserole
- While the squash is roasting, brown the sausage and onions together in 1 tablespoon olive oil, until the sausage is cooked through. Add in the garlic and oregano and saute for 1-2 minutes longer. Remove from heat and drain off excess grease.
- Add sausage mixture, whisked eggs, and 2 cups of the sauce to the spaghetti squash and mix well.
- Transfer mixture to an 8x8 dish and cover with remaining 1 cup of sauce. If using cheese, sprinkle evenly over the casserole at this time.
- Bake for 1 hour at 350 degrees or until top is bubbly and browned.
Equipment Needed
Notes
- Sausage: Use ground Italian sausage. Pork, chicken, or turkey all work well in this casserole. Just be sure to read the ingredients in your sausage as some brands have added gluten or sugar.
- Spaghetti sauce--Be sure to omit sugar from homemade sauce or use no added sugar sauce to keep this Paleo Friendly.
- Spaghetti squash: In place of roasting the squash, use my method for cooking spaghetti squash in the Instant Pot, by cutting in half, removing the seed, and cooking on high pressure for 7 minutes. Be sure to place your squash on a trivet over 1.5 cups of cold water.
- Cheese: If you are not dairy-free or following a paleo diet, I suggest adding 1 cup of shredded Mozzarella and 1/4 cup Parmesan cheese to the top of this casserole.
This might be a silly question but are you really supposed to cook it for 1 hour at 30 degrees or is that supposed to be 350 (as it stated in the first step 2 “reduce heat to 350”? Excited to try this for dinner. Thank you
Hi Taylor! Not a silly question at all–that was an error. I have corrected it to say 350 degrees 🙂 Enjoy!
I made this as written except for microwaving the spaghetti squash the day before just to save time (I have a baby who takes up all our weeknight time!). I’m not sure I would recommend this over roasting because the casserole was very liquidy! Did you find that at all? It was still delicious and even my husband who says he hates spaghetti squash, said this was okay (trust me, that’s a compliment). I did top with dairy-free cheese. Because of the liquid it was more like a stew I would say but still very tasty! Thanks!
I love how you multi-tasked and made the spaghetti squash before! My squash is typically not that watery, so that may have been part of the issue. It may also have been your tomato sauce was thinner. In the future, drain off excess liquid from your squash and then add only enough tomato sauce to coat. Hope that helps! And glad you and your husband (sort of 😉) enjoyed!
I’m trying to eat healthier in the new year, and this DELICIOUS spaghetti squash casserole fit in perfectly with my new goal. My entire family LOVED it, I will definitely make it again!
That makes me so happy to hear Jillian!
I love having a recipe using spaghetti squash that isn’t spaghetti! Definitely a keeper!
This looks like an awesome weeknight meal, I know my family would love this. I love spaghetti squash – it’s so versatile!
Spaghetti Squash really is so amazing Sara! Enjoy!