If you are looking to fall in love with a vegetable all over again, this Cheesy Vegetarian Spaghetti Squash Casserole Recipe is exactly what you need. It takes the naturally mild, slightly sweet strands of roasted spaghetti squash and combines them with creamy ricotta, sharp Parmesan, fresh spinach, and bubbly melted mozzarella to create a comforting, healthy, and irresistibly cheesy dish. This casserole is refreshing because it’s not your typical pasta bake—it’s lighter, packed with veggies, and still satisfies that craving for rich, gooey cheese goodness in every bite. Trust me, once you try this casserole, it’s going to become your go-to recipe for cozy dinners that feel indulgent but are still vegetarian-friendly and nutritious.
Ingredients You’ll Need
Nothing complicated here, just simple, fresh ingredients that come together perfectly to build layers of flavor, texture, and color in this casserole. Each ingredient plays a key role, from the tender squash strands providing the base, to the cheeses adding creamy and tangy richness, and the spinach giving a lovely pop of green and a nutrient boost.
- 1 medium spaghetti squash: The star of the show, roasted until tender and easily shredded into noodle-like strands.
- 1 tablespoon olive oil: Helps crisp the squash edges slightly and adds a subtle fruity richness.
- Salt and pepper, to taste: Essential to bring out the natural flavors and balance the creaminess.
- 1 cup ricotta cheese: Adds a smooth, mild creaminess that blends beautifully with the pasta strands.
- 1 large egg white: Acts as a binder to keep the casserole firm but light.
- ½ cup freshly grated Parmesan cheese: Introduces a sharp, nutty complexity and golden crust when baked.
- 2 cups fresh spinach, chopped: For freshness, color, and a subtle earthy taste that brightens the dish.
- 1 teaspoon Italian seasoning: Brings in hints of oregano, basil, and thyme for classic Italian flair.
- ½ teaspoon garlic powder: Delivers gentle garlicky warmth without overpowering the delicate squash.
- 1 cup shredded mozzarella cheese: Melts to velvety perfection, creating that irresistible cheesy topping.
- Fresh parsley, chopped (optional, for garnish): Adds a vibrant burst of color and fresh herbal notes at the end.
How to Make Cheesy Vegetarian Spaghetti Squash Casserole Recipe
Step 1: Roast the Spaghetti Squash
Start by preheating your oven to 400°F (200°C). Carefully slice the spaghetti squash in half lengthwise and scoop out the seeds. Drizzle the cut sides with olive oil and sprinkle with salt and pepper. Place the halves cut-side down on a baking sheet lined with parchment paper and roast for 40-45 minutes. You want the flesh tender enough to shred easily with a fork—this roasting process brings out the natural sweetness and gives the squash that perfect soft texture.
Step 2: Shred the Squash
After roasting, let the squash cool just enough to handle safely. Use a fork to scrape the flesh into spaghetti-like strands. Set it aside while you prepare the cheesy filling. Getting this right means you’ll have those beautiful noodle-like strands that make the casserole feel like a real pasta dish, without any actual pasta.
Step 3: Mix the Ricotta Spinach Filling
In a large bowl, combine the ricotta cheese, egg white, freshly grated Parmesan, chopped spinach, Italian seasoning, garlic powder, and a pinch of salt and pepper. Stir everything together until smooth and well combined. This mixture is creamy, flavorful, and a wonderful contrast to the lightly textured squash noodles.
Step 4: Assemble the Casserole
Grease a 9×13-inch baking dish lightly. Spread the shredded spaghetti squash evenly across the bottom—this forms a delicious base layer. Next, spread the ricotta-spinach filling evenly over the squash. Finally, sprinkle the shredded mozzarella cheese on top to ensure a golden, gooey finish once baked.
Step 5: Bake to Perfection
Reduce the oven temperature to 350°F (175°C). Place the casserole in the oven and bake for 25-30 minutes, or until the cheese topping is melted and bubbling with a beautiful golden color. Remove from the oven and let it rest for about 5 minutes before serving—this helps the casserole set and makes it easier to slice.
Step 6: Garnish and Serve
If you like, sprinkle chopped fresh parsley over the top for a fresh and colorful finishing touch. Then slice, serve, and enjoy your masterpiece of cheesy comfort and healthy veggies.
How to Serve Cheesy Vegetarian Spaghetti Squash Casserole Recipe
Garnishes
A sprinkle of freshly chopped parsley adds a peek of vibrant green that makes every serving inviting and fresh. For some extra zing, you can also add a little cracked black pepper or even a dusting of extra Parmesan cheese right before serving. These simple touches elevate the presentation and flavor beautifully.
Side Dishes
This casserole shines as a satisfying main dish but pairs wonderfully with light and bright sides. A crisp green salad with lemon vinaigrette or a refreshing cucumber and tomato salad complements the richness of the cheese while balancing the meal perfectly. Alternatively, roasted vegetables or garlic bread make comforting, tasty companions.
Creative Ways to Present
For a fun twist, try serving individual portions in small ramekins. This makes for a charming presentation, especially if you’re entertaining guests. You could also use colorful heirloom tomatoes or grilled zucchini slices as edible “plates” for a fresh and elegant look. No matter how you present it, this casserole is always a crowd pleaser.
Make Ahead and Storage
Storing Leftovers
Store any leftover Cheesy Vegetarian Spaghetti Squash Casserole Recipe in an airtight container in the refrigerator. It will keep well for 3 to 4 days, making it a perfect make-ahead meal for busy weeknights. To maintain the best texture, avoid storing the casserole with topping garnishes like fresh parsley—add those fresh when you serve.
Freezing
You can freeze this casserole for up to 2 months. For best results, freeze it before baking by preparing it fully and wrapping the baking dish tightly in plastic wrap and aluminum foil. When you’re ready to enjoy, thaw overnight in the refrigerator and then bake as usual, adding a little extra time if still partially frozen.
Reheating
Reheat individual portions in the microwave until warmed through and the cheese is melty again. Alternatively, reheat the whole casserole in a 350°F (175°C) oven for about 15-20 minutes, covered with foil to keep moisture in. Remove the foil in the last few minutes if you want to refresh the bubbly cheesy top.
FAQs
Can I use frozen spinach instead of fresh in this casserole?
Absolutely! Just be sure to thaw and squeeze out as much liquid as possible before adding it to the ricotta mixture. This prevents the casserole from becoming watery and keeps the flavors vibrant.
Is it possible to make this casserole vegan?
Yes, by substituting the ricotta and mozzarella with plant-based cheeses and using a flax egg instead of a traditional egg white, you can create a delicious vegan version without sacrificing the creamy texture.
Can I add other vegetables to this casserole?
Definitely! Feel free to mix in sautéed mushrooms, bell peppers, or even some roasted cherry tomatoes for extra flavor and texture. Just be careful not to add too much moisture-heavy veggies unless you cook them beforehand.
How do I know when the spaghetti squash is done roasting?
Roast until the flesh is tender enough to shred easily with a fork—this usually takes 40 to 45 minutes at 400°F. The strands should separate effortlessly and have a slight softness without being mushy.
What’s the best way to serve leftovers?
Leftover casserole tastes great cold or reheated. For an easy lunch, slice and stack it with some fresh greens or use it as a filling for warm wraps. It’s perfect for meal prep and holds its flavor beautifully.
Final Thoughts
This Cheesy Vegetarian Spaghetti Squash Casserole Recipe is a delightful way to enjoy a vegetable that might not get enough love on your table. It feels indulgent but is actually wholesome, packed with vibrant veggies and rich cheeses that make every bite a treat. Give this recipe a try—you’ll soon find yourself coming back to it again and again for a cozy, satisfying meal that’s both comforting and nourishing.
Print
Cheesy Vegetarian Spaghetti Squash Casserole Recipe
- Prep Time: 15 minutes
- Cook Time: 70 minutes
- Total Time: 85 minutes
- Yield: 8 servings
- Category: Casserole
- Method: Baking
- Cuisine: American
- Diet: Vegetarian
Description
This Cheesy Vegetarian Spaghetti Squash Casserole is a delicious and healthy comfort food option that features roasted spaghetti squash strands layered with a creamy ricotta-spinach mixture and topped with melted mozzarella cheese. Perfectly seasoned and baked to bubbly golden perfection, this casserole makes a satisfying meal suitable for vegetarians and those looking for a low-carb alternative to traditional pasta dishes.
Ingredients
Spaghetti Squash
- 1 medium spaghetti squash
- 1 tablespoon olive oil
- Salt and pepper, to taste
Ricotta Mixture
- 1 cup ricotta cheese
- 1 large egg white
- ½ cup freshly grated Parmesan cheese
- 2 cups fresh spinach, chopped
- 1 teaspoon Italian seasoning
- ½ teaspoon garlic powder
- Salt and pepper, to taste
Topping
- 1 cup shredded mozzarella cheese
- Fresh parsley, chopped (optional, for garnish)
Instructions
- Preheat the Oven: Preheat your oven to 400°F (200°C) to prepare for roasting the spaghetti squash.
- Prepare the Squash: Slice the spaghetti squash in half lengthwise and remove all seeds. Drizzle the cut sides with olive oil and season with salt and pepper to enhance flavor.
- Roast the Squash: Place the squash halves cut-side down on a baking sheet lined with parchment paper. Roast in the oven for 40-45 minutes until the flesh is tender and easily shredded with a fork.
- Scoop the Squash: Once slightly cooled, use a fork to scrape the roasted squash flesh to form spaghetti-like strands. Set aside for layering.
- Make the Ricotta Mixture: In a large bowl, combine ricotta cheese, egg white, Parmesan cheese, chopped spinach, Italian seasoning, garlic powder, salt, and pepper. Mix thoroughly until well blended.
- Assemble the Casserole: Grease a 9×13-inch baking dish. Spread the shredded spaghetti squash evenly across the bottom as the base layer.
- Add Ricotta Layer: Spread the prepared ricotta-spinach mixture evenly over the spaghetti squash layer.
- Top with Cheese: Sprinkle shredded mozzarella cheese evenly over the ricotta mixture for a cheesy topping.
- Adjust Oven Temperature: Lower the oven temperature to 350°F (175°C) in preparation for baking the assembled casserole.
- Bake the Casserole: Bake for 25-30 minutes until the cheese is fully melted, bubbly, and slightly golden on top.
- Rest and Serve: Remove the casserole from the oven and allow it to rest for 5 minutes before serving to let flavors settle.
- Garnish and Enjoy: Optionally garnish with freshly chopped parsley. Slice into portions and enjoy your cheesy, nutritious vegetarian casserole!
Notes
- Spaghetti squash can be replaced with butternut squash or zucchini noodles for variation.
- For a richer texture, use whole eggs instead of just egg whites.
- Fresh spinach can be substituted with kale or Swiss chard if preferred.
- To make this dish vegan, replace ricotta and mozzarella with plant-based cheese alternatives and omit the egg white.
- Leftovers can be stored in an airtight container in the refrigerator for up to 3 days and reheated in the oven.
