Delicious Vegetarian Spaghetti Squash Casserole Recipe

Welcome to my delicious Vegetarian Spaghetti Squash Casserole Recipe! If you’re looking for a flavorful and hearty meal that is both healthy and easy to make, you’ve come to the right place. At the heart of this recipe is the versatile and nutrient-packed spaghetti squash, which we’ll be stuffing with a combination of creamy spinach and mushrooms, topped with cheesy goodness before baking it to perfection.

This casserole recipe is perfect for a cozy dinner at home or for sharing with friends and family. As someone who has experimented with different diets throughout my life, I know how hard it can be to come up with tasty and satisfying vegetarian options. That’s why I’m excited to share this crowd-pleasing recipe that will have even meat-lovers coming back for seconds.

Plus, not only is this Vegetarian Spaghetti Squash Casserole delicious, but it’s also gluten-free and can easily be made vegan by leaving out the cheese and eggs. So no matter what dietary restrictions you have, you can enjoy this wholesome and flavorful casserole bake!

Are you ready to dig in? Let’s get started on making this delectable Vegetarian Spaghetti Squash Casserole Recipe!

Why You’ll Love This Recipe

Vegetarian Spaghetti Squash Casserole
Vegetarian Spaghetti Squash Casserole

Are you looking for a healthy and comforting meal that’s both satisfying and nutritious? Look no further than this Vegetarian Spaghetti Squash Casserole Recipe! You don’t have to be a vegetarian to appreciate the flavors and textures of this dish.

First of all, this spaghetti squash casserole is incredibly versatile. Whether you’re gluten-free or vegan, you can still enjoy this dish without sacrificing any flavor. And if you’re on a low-carb or keto diet, this recipe is perfect for you!

But what makes this recipe truly special is the combination of ingredients. The creamy spinach, savory mushrooms, and sweet onions create a delicious base for the cheesy spaghetti squash. The oregano adds a touch of Mediterranean flair while the extra virgin olive oil brings out the richness of the ingredients. This casserole bake recipe also features garlic minced to perfection, adding another layer of depth to the dish.

And let’s not forget about the cheese! Whether you choose goat cheese or Parmesan cheese, the cheesy element of this dish will leave your taste buds dancing with joy. Finally, eggs are added to give extra creaminess and nutritional value.

So if you’re looking for a dish that’s both delicious and healthy, give this Vegetarian Spaghetti Squash Casserole Recipe a try! It’s perfect for any occasion – whether it’s a family dinner or a party with friends. Trust me, it won’t disappoint!

Ingredient List

“This spaghetti squash casserole is like a cozy blanket of comfort food.”

Let’s take a look at the ingredients you’ll need for this mouth-watering Vegetarian Spaghetti Squash Casserole Recipe:

  • 1 medium spaghetti squash: This is the star of the show, and it’s important to choose a medium-sized one that’s ripe and firm.
  • 4 cups of mushrooms: This gives the casserole a meaty texture and is rich in umami flavor.
  • 1 small sweet onion, chopped: This adds sweetness to the dish and balances out the umami flavor from the mushrooms.
  • 2 garlic cloves, minced: Garlic is essential in any Italian-style dish. It adds depth of flavor and richness.
  • 2 cups of creamy spinach: This provides freshness to the dish and balances out some of the heaviness.
  • 1/2 cup diced tomatoes: This adds acidity and brightens up the flavors.
  • 2 tablespoons extra-virgin olive oil: This is used for sautéing vegetables and keeping them from sticking to the pan.
  • 1 teaspoon oregano: This herb packs a punch and adds tons of earthy, savory flavor.
  • 1/2 teaspoon salt: Salt brings out all of the flavors in this dish, so make sure not to skip this ingredient!
  • 1/3 cup parmesan cheese (optional): If you’re not vegan, parmesan cheese can add a salty, nutty flavor to your casserole.

The Recipe How-To

“Who needs pasta when you have delicious, nutritious spaghetti squash?”

Now that we have gone over the ingredient list for this Vegetarian Spaghetti Squash Casserole Recipe, it’s time to get cooking! Follow these steps for a hearty and delicious meal.

Step 1: Prepping the Squash

  • I first halve the spaghetti squash lengthwise and scoop out the seeds.
  • Then, I brush both halves of the squash with olive oil and sprinkle some sea salt on them.
  • I place them cut side down on a baking sheet lined with parchment paper.
  • Roast in the oven at 375°F for 45-50 minutes until they are fork-tender.
  • Let them cool for at least 5 minutes before using a fork to scrape out the strands of flesh.

Step 2: Preparing the Rest of the Ingredients

  • While spaghetti squash is roasting, I slice mushrooms, dice an onion, and mince some garlic cloves.
  • Next, I sauté these vegetables in a pan with some olive oil until they are soft and slightly caramelized.
  • To make my vegetarian casserole more flavorful, I add some oregano , sea salt, and freshly ground black pepper.

Step 3: Putting it All Together

  • In a large mixing bowl, I whisk together eggs, parmesan cheese, cooked spinach spaghetti squash, and your sautéed mixture from Step 2.
  • Once well combined, add in your cooked & prepared spaghetti squash. Mix everything thoroughly.
  • Pour into a large greased baking dish or casserole dish
  • Bake for approximately 40-45 minutes or until the edges turn golden brown.

With all the nutritious ingredients that this cheesy vegetarian casserole bake recipe has to offer, you can feel good about enjoying every bite!

Substitutions and Variations

“Dig into a bowl of cheesy, veggie-packed goodness with this casserole.”

Let’s start with the ingredients. If you have dietary restrictions or preferences, there are plenty of tasty substitutions you can make for this vegetarian spaghetti squash casserole recipe.

For a vegan spin on the recipe, simply swap out the cheese and eggs for a vegan alternative. You can find vegan cheese and egg substitutes at most supermarkets or specialty stores. Another option is to use extra veggies like chopped bell peppers, zucchini, or eggplant as alternatives to cheese.

If you’re looking for a gluten-free option, use gluten-free pasta instead of traditional spaghetti. Brown rice spaghetti is an excellent gluten-free substitute and has a similar taste and texture to traditional pasta.

If you’re a mushroom lover, consider adding different types of mushrooms to the casserole, such as chanterelles or portobellos. This would add an earthy depth to the dish that pairs well with oregano and spinach.

If you enjoy a little bit of heat in your meals, try adding red pepper flakes or cayenne pepper to your casserole mix. These spices add a spicy kick that complements the creamy spinach spaghetti squash wonderfully.

Finally, if you want to up your protein intake, consider adding some chickpeas or tofu into the mix. They complement the cheesy and savory taste of this meal without overpowering it.

Experimenting with these substitutions will help create unique variations suited to your dietary needs and personal preferences. The success of cooking is all about trying new things!

Serving and Pairing

“This dish is perfect for those chilly fall evenings when you need something warm and filling.”

Now that you have successfully baked a cheesy vegetarian spaghetti squash casserole, it’s time to serve it up and enjoy the delicious flavors.

This casserole is an excellent vegetarian dinner option that can be served as the main course on any occasion. I recommend serving this casserole with a side salad or garlic bread to complete your meal. A glass of red wine or sparkling water with lime will also pair well with this dish.

If you’re looking for additional ways to enjoy this recipe, try serving it as a side dish to roast chicken or grilled vegetables. You can also use this casserole as a hearty base for mushroom bolognese or sausage meat sauce. The possibilities are endless.

One thing to keep in mind when pairing this casserole is that it is already packed with flavor and cheese, so opt for lighter sides and beverages to avoid overloading your palate.

Whether you’re enjoying this casserole as a vegetarian main course or a side dish, it’s sure to be a crowd-pleaser. So go ahead and experiment with different serving ideas until you find the perfect match for your taste buds.

Make-Ahead, Storing and Reheating

“Get your veggies and your comfort food fix all in one dish with this recipe.”

As a busy vegan chef, I know the importance of being able to prepare meals in advance. The good news is that this Vegetarian Spaghetti Squash Casserole recipe is perfect for making ahead of time. You can easily prepare it a day or two in advance, then cover tightly with foil and refrigerate until ready to bake.

Storing the casserole is also straightforward – simply store any leftovers in an airtight container in the refrigerator for up to 3 days. To reheat, preheat your oven to 350°F (175°C), cover the casserole with foil and bake for about 15-20 minutes or until heated through.

If you’re someone who loves meal prepping or batch cooking, this recipe can be doubled and cooked in two smaller baking dishes. Simply wrap them tightly with plastic wrap or aluminum foil and freeze for up to three months. When you’re ready to enjoy your frozen casserole, defrost it overnight in the fridge before reheating as above.

If you’re afraid that spaghetti squash may get watery after freezing, don’t worry! This recipe won’t suffer from ice crystal buildup since we have already cooked the spaghetti beforehand.

Whether it’s for a quick dinner on a busy weeknight or meal prep for the upcoming week, this vegetarian casserole is ideal for making ahead of time without comprising its taste and quality.

Tips for Perfect Results

“One bite of this flavorful casserole and you’ll forget it’s even vegetarian.”

When it comes to making the perfect spaghetti squash casserole, there are a few key tips to keep in mind. Here are my top recommendations for ensuring that your dish turns out delicious, flavorful, and perfectly cooked every time.

First, make sure to prepare your spaghetti squash properly. This means cutting it open carefully and scooping out the seeds and pulp, then seasoning the flesh with olive oil, salt, and pepper before roasting it in the oven. Roast until the squash is tender, roughly 35-45 minutes depending on size.

For an extra burst of flavor, consider adding diced onion and garlic to your casserole filling. These aromatic ingredients will infuse the entire dish with their rich flavors and aromas, making every bite even more satisfying.

Another important tip is to be creative with your toppings. Whether you prefer a cheesy vegan or vegetarian option or want to try something different like broccoli casserole or mushroom bolognese. Play up what you have on hand!

Most importantly don’t be afraid to experiment! Cheesy spaghetti squash lasagna bake? Low-carb ground beef-stuffed spaghetti squash? Parmesan meat sauce spaghetti squash? All perfect dishes make use of this versatile vegetable. Feel free to mix-and-match ingredients to find the perfect combination for you and your family.

By following these tips and playing around with different variations of the recipe, you’ll be able to create a spaghetti squash casserole that’s truly unforgettable. Enjoy!

Bottom Line

And there you have it, fellow food enthusiasts! My Vegetarian Spaghetti Squash Casserole recipe is undoubtedly a crowd-pleaser, and I trust that you’ll love it as much as I do. With its delicious blend of textures and flavors, this dish is perfect for any mealtime, whether it’s lunch, dinner or even breakfast.

Not only is this casserole satisfying to the palate, but it’s also a healthy alternative to traditional pasta dishes. With its gluten-free and low-carb options, my recipe ensures that vegetarians and vegans alike can enjoy their pasta cravings while watching their waistlines.

Moreover, I’ve provided you with various substitutions and variations that allow for customization based on your personal taste buds. Whether you add goat cheese, parmesan cheese, sausage or ground beef to the mix, the possibilities are endless!

So go ahead and give it a try. Treat yourself to a hearty, nutritious meal that’s easy to make and bursting with cheesy goodness!

Vegetarian Spaghetti Squash Casserole

Vegetarian Spaghetti Squash Casserole Recipe

I invented this recipe after searching for a spaghetti squash recipe that was vegetarian and included ingredients that I had on hand and not finding one. I was quite surprised at how much my kids and husband all liked it (and even fought over who would take leftovers to school the next day). Even the daughter who swore she didn't like spaghetti squash was surprised how much she liked it.
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Prep Time 30 mins
Cook Time 55 mins
Course Main Course
Cuisine Vegetarian
Servings 1 casserole
Calories 146.2 kcal


  • 1 spaghetti squash
  • 2 -3 cups chopped vegetables (I used red peppers, onions, and cauliflower, but others would work)
  • 1 tablespoon olive oil
  • 1/2 teaspoon oregano
  • salt & pepper
  • 2 eggs
  • 1/4 cup cream (optional)
  • 1 cup shredded cheese (I used a combination of feta cheese and sharp cheddar, others would work too)


  • Cut the spaghetti squash in half and scoop out the seeds. Place the squash cut side down in a cake pan or casserole dish. Add about half an inch of water and cover with tinfoil. Roast it in a 375 degree oven for approximately 30 minutes or until tender.
  • Chop up the vegetables and place them in a separate casserole dish. Sprinkle the olive oil, oregano, and salt and pepper over them, and roast them at the same time as the squash.
  • In the meantime, beat the eggs and add the cream and shredded cheese.
  • Once the squash is tender, scoop it out of the peel and add it to the roasted vegetables in the casserole dish. Add the egg and cheese mixture and stir it inches.
  • Return it to the oven and bake uncovered for approximately 25 minutes.

Add Your Own Notes


Serving: 118gCalories: 146.2kcalCarbohydrates: 6.2gProtein: 7.3gFat: 10.5gSaturated Fat: 4.5gCholesterol: 88.9mgSodium: 257.1mgSugar: 0.1g
Keyword < 4 Hours, Canadian, Easy, From Scratch, Vegetable
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