I have been making this spaghetti squash casserole for going on five years now and I think it’s safe to say at this point that it is in the top 10 when it comes to the number of times that I’ve made a specific recipe.
I have hesitated to share the recipe on my blog because it’s an adaptation of another blogger’s recipe. I have come to realize that while I still give her 100% credit for creating the recipe, the changes that I have made are my own and they are too complicated/involved to try and type out every time I mention making it on my blog. I just want to have a post that I can link to that spells out my adaptations of the AMAZING PaleOMG pizza spaghetti pie.
That said, welcome to the most delicious spaghetti squash casserole of your life. I don’t even know how it’s possible but this recipe really does taste like pizza. It’s kinda crazy. There is not one single person that I have introduced to this recipe that has not loved it and gone on to start making it themselves.
It’s an excellent dish to serve if you’re hosting dinner guests and also perfect as a drop-off meal for a friend as it’s easy to transport and heats over well.
I think I first learned about PaleOMG Pizza Spaghetti Pie when I was doing my first Whole30 but these days I go all out with modifications to the original 5-ingredient recipe. I can’t help myself and the recipe is very versatile.
Even though the recipe is simple, this spaghetti squash casserole does requires multiple steps to prep in that you have to bake the spaghetti squash first and then sauté the other ingredients on the stovetop. I promise that it’s all simple stuff and worth the effort. This is one of those recipes where the leftovers almost taste better than the first time you eat it so definitely plan to make two dinners out of it!
Topping the casserole with pepperoni and cheese is optional but I’m in the camp of let’s make it as pizza as possible!! 🙂
When I made the recipe this week I was shocked that Finn gobbled it up! My carb-loving, veggie-disliking boy not only ate what was on his plate but asked for MORE! While I am not always a fan of hiding/disguising veggies (I go for a mix of both approaches), I appreciate recipes like this where the veggies are front and center. This casserole includes spaghetti squash, tomatoes, mushrooms, onions, eggs, cheese, chicken sausage and more. Awesome to get all of that into one dish!
I am sharing my spin on the original recipe below but please feel free to put your own on it! This recipe is so adaptable. I have used different types of pasta sauces (the Trader Joe’s season Autumnal Sauce is SO good in this dish!), different types of cheese and different types of veggies. Some veggies that I’ve loved including are artichoke hearts and chopped spinach. Basically, anything that you’d top a pizza with would probably work great.
The BEST EVER Spaghetti Squash CasserolePrint
A delicious pizza-inspired spaghetti squash casserole that is loaded with veggies and flavor!
1 large spaghetti squash
2 tablespoons olive oil
1 pound Italian sausage (I usually use chicken sausage but pork is fine too)
1 sweet or yellow onion, finely diced
8 ounces mushrooms, thinly sliced
2 cloves garlic, minced
12–16 ounces marinara sauce (1 1/2–2 cups)
1 teaspoon Italian seasoning
1/2 teaspoon red pepper flakes (optional but I like the kick, I leave it out if serving to Finn)
Salt and pepper, to taste
3 eggs, whisked
1/3 cup grated parmesan cheese (optional can leave out if dairy-free)
Additional veggies as desired: chopped spinach, artichoke hearts, peppers, etc)
15–20 mini pepperoni (optional)
1–2 cups shredded cheese for topping (optional can leave out if dairy-free)
- Preheat oven to 350 degrees.
- Cut spaghetti squash in half lengthwise. Place spaghetti squash cut side down in a baking dish with an inch or so of water. It’s done cooking when the skin pierces easily and feels soft. Note, you almost want to slightly undercook the squash as it’s going to cook again in the casserole. You don’t want your “noodles” to be mushy.
- Once squash is done cooking, remove threads using a fork and set aside.
- Place a large pan over medium heat. Add olive oil and then sausage, mushrooms and onions. Cook until the sausage is no longer pink. Be sure to break it into pieces with your spoon or spatula while cooking. Add garlic and cook another minute or so, careful not to let it burn. Add marinara to pan, as well as Italian seasoning, red pepper flakes and salt and pepper to taste.
- Add the spaghetti squash noodles and mix to combine. (Note, if your pan isn’t big enough to accommodate noodles and sausage mixture, you might want to transfer everything to a large bowl.
- Add whisked eggs and grated parmesan to the mix and stir everything together until well-incorporated. Prepare a square 8×8 or 9×9 baking dish (I actually use a 9x12ish rectangular baker and it works great!) by spraying with nonstick cooking spray or oiling down with olive oil. Spread spaghetti squash mixture into prepared baking dish. Add toppings of your choice.
- Place in oven and bake for 1 hour or until the top of the mixture forms a slight crust that doesn’t give when you press on it in the middle of the dish. If you have topped with cheese, you might want to cover with foil for first 40 minutes of baking and uncover for last 20.
- Let rest for 5 minutes before serving.
Feel free to play around with different variations when it comes to veggies and toppings.
Leftovers reheat very well.
Keywords: best spaghetti squash casserole