Growing up, baked casseroles were always a comfort for me—warm, creamy, and perfect for cold evenings.
When I first swapped in spaghetti squash instead of pasta, I was amazed by how light yet satisfying it was.
This spaghetti squash casserole has since become a staple in my weeknight rotation.
Why I Love This Spaghetti Squash Casserole
It’s the ultimate balance of healthy and comfort.
Naturally gluten-free and easy to adapt for low-carb diets.
Great way to use up leftover squash or make ahead for meal prep.
Creamy, cheesy, and packed with flavor.
What You’ll Need (Ingredient Highlights)
Spaghetti squash – The base of our casserole, with a naturally tender and noodle-like texture.
Olive oil – Helps caramelize the squash and onions for extra depth.
Onion & garlic – Add essential savory notes.
Greek yogurt or sour cream – For creaminess without heavy cream.
Sharp cheddar cheese – Melts beautifully and gives bold flavor.
Seasonings – Salt, pepper, and optional paprika or thyme for extra dimension.
Pro Tips Before You Start
Use a sharp chef’s knife to carefully cut the squash in half—microwaving for 3–5 minutes first makes this much easier.
Roast squash face-down to trap moisture and create a more tender texture.
Let the squash cool before shredding to avoid burning your hands.
Squeeze out extra moisture from the squash strands if they seem watery—this helps avoid a soggy casserole.
How to Make Spaghetti Squash Casserole
Step 1. Roast the Spaghetti Squash
Preheat oven to 400°F (205°C).
Carefully cut the squash in half lengthwise and scoop out the seeds.
Brush the cut sides with olive oil and place cut-side down on a baking sheet.
Roast for 35–40 minutes, or until the flesh is fork-tender.
Step 2. Sauté the Aromatics
While the squash is roasting, heat a skillet with a little olive oil.
Add diced onions and cook until softened—about 5 minutes.
Add minced garlic and sauté for 1 more minute. Remove from heat.
Step 3. Shred the Squash
Once cool enough to handle, use a fork to gently scrape out the squash flesh into spaghetti-like strands.
Step 4. Mix the Casserole Base
In a large mixing bowl, combine shredded squash, sautéed onions and garlic, Greek yogurt (or sour cream), 1 cup of shredded cheddar, salt, pepper, and your choice of paprika or thyme.
Step 5. Assemble & Bake
Transfer the mixture into a greased casserole dish.
Sprinkle the remaining ½ cup of cheese evenly on top.
Bake at 375°F (190°C) for 20–25 minutes, or until bubbling and golden brown on top.
Step 6. Cool & Serve
Let it rest for 5 minutes before serving—this helps the cheese set slightly for easier scooping.
What to Serve It With
A crisp green salad with balsamic vinaigrette
Roasted chicken or grilled sausages
Garlic bread or a warm dinner roll (if not avoiding carbs)
Variations / Substitutions
Swap cheddar for mozzarella or Gruyère for a different cheese profile.
Add cooked bacon bits or rotisserie chicken for extra protein.
Use sour cream instead of Greek yogurt for a tangier finish.
Toss in some chopped spinach or kale for added greens.
Storage & Leftovers
Fridge: Store leftovers in an airtight container for up to 4 days.
Reheat: Warm in the oven at 350°F or microwave in short bursts.
Freezer: This dish freezes well! Wrap tightly and freeze for up to 2 months. Thaw before baking.
FAQs
Can I prep this spaghetti squash casserole ahead of time?
Yes! You can assemble it a day ahead, cover, and store in the fridge. Bake just before serving.
Can I freeze the casserole?
Absolutely. Let it cool completely, then wrap and freeze.
Thaw in the fridge overnight before reheating.
What’s the best way to cut spaghetti squash?
Microwave it for 3–5 minutes to soften the skin, then slice carefully with a large knife.
Can I use pre-cooked spaghetti squash?
Yes, just skip the roasting step and jump straight to sautéing your aromatics.
What if my casserole is watery?
Make sure to squeeze or blot extra moisture from the squash strands before mixing.
Can I use other vegetables?
You can add mushrooms, spinach, or zucchini—but sauté them first to avoid added moisture.
Is this casserole low-carb or keto?
It’s naturally lower in carbs than pasta casseroles, but you can reduce carbs further by skipping the onions and using full-fat ingredients.
Final Thoughts
This spaghetti squash casserole is everything I want in a feel-good meal—comforting, cheesy, and full of flavor, but without the heaviness.
It’s the perfect way to enjoy squash in a fun and satisfying new way.
Once you try it, I’m sure it’ll earn a regular spot at your dinner table just like it did at mine.
