This baked Spaghetti Squash Casserole is an easy, low-carb, pasta-style dish the whole family will love. You know those dinners that manage to tick every box — cosy, hearty, comforting, yet still light enough to leave you feeling good? That’s exactly what this recipe delivers. And it even tastes better as reheated leftovers! It’s a baked dish of tender roasted spaghetti squash tossed with a quick and easy tomato-meat sauce, topped with a layer of cheese, and finished in the oven until everything is golden, melted, and bubbling. The result? All the flavour and comfort of a classic pasta bake, but just a little lighter, fresher, and perfectly wholesome version.
Think of it as a low-carb twist on baked pasta, only instead of noodles, we have delicate strands of roasted spaghetti squash that make this dish feel nourishing, satisfying, and honestly just really delicious.
What You’ll Need to Make This Spaghetti Squash Casserole
This is one of those casserole recipes that’s built from humble, everyday ingredients. Nothing fancy, just good, honest ingredients that come together to make something wholesome and satisfying.
- Spaghetti squash: After roasting, run a fork through the flesh and watch it transform into long, thin, spaghetti-like strands. The trick? Don’t overcook it! You want a little bite, like al dente pasta.
- Ground beef: Gives the sauce a hearty, savoury richness.
- Onion and garlic: The aromatic base for any good sauce.
- Tomatoes + tomato paste: For that slow-simmered depth of flavour in a quick way.
- Italian herbs + chilli flakes: Because flavour matters.
- Gouda + Parmesan: A creamy, melty duo that brings the whole dish together.
- Fresh herbs: A little sprinkle of parsley or basil adds a pop of colour and freshness.
How to Make My Spaghetti Squash Casserole
This recipe has just 3 main steps and they’re all easy. The hardest part? Waiting for it to bake while your kitchen starts smelling incredible.
1) Roast the squash.
Start by brushing the squash with a little olive oil and roast it cut-side down. This usually takes about 45 minutes, depending on the size. You’ll know it’s ready when the cut sides are turning golden and the interior is easily pierced through with a fork.
2) Make the sauce.
While the squash does its thing, use an ovenproof skillet to cook the onion and garlic until soft and fragrant. Add the beef and let it brown, then stir in the tomato paste, herbs, and crushed tomatoes. Let it simmer while the squash finishes baking.
3) Combine and bake.
Fold the squash strands into the sauce, spread everything into a baking dish, and finish with a generous handful of cheese. Bake until the top is melted, golden, and bubbling around the edges — the kind of bubbling that makes it hard to wait before digging in!
Get the exact ingredient quantities in the printable recipe card below.
How to Adapt My Spaghetti Squash Casserole
One of the things I love most about this spaghetti squash casserole is how adaptable it is. Here are a few ways to make it your own without losing that cosy, baked comfort we all love.
1) Swap the squash.
If spaghetti squash isn’t available, don’t worry as other types of winter squash work beautifully here too. Butternut squash is my favourite swap. It’s slightly sweet and velvety, and while it won’t give you the noodle-like strands, it bakes into a rich, silky base that feels wonderfully comforting. Just roast it until tender, scoop out the flesh, and fold it into the sauce for a cosy bake.
2) Play with the cheese.
Gouda and Parmesan give this casserole its classic, creamy flavour, but feel free to experiment. Swiss Bergkäse, Gruyère, Comté, or even mozzarella all melt beautifully and bring their own distinct richness. Mix and match depending on your mood (or what’s left in the fridge).
Why I Love This Spaghetti Squash Casserole
If you’re new to cooking with spaghetti squash, this casserole recipe is the perfect way to start. It’s everything you might love about baked pasta, but it’s much lighter, has less calories and is low-carb.
- All the comfort, without all those carbs — You get the cosy, cheesy bake you crave, without pasta or gluten.
- Meal-prep friendly — It reheats beautifully, making leftovers feel like a gift.
- Simple ingredients — Everyday staples that somehow make magic together.
- Family-approved — Kids love it, and adults go back for seconds.
- Customisable — Add more veggies, change up the cheese — it’s forgiving and flexible.
If baked, feel-good comfort food is your thing, you’ll love these other wholesome dishes. Each one is packed with flavour and delivers that same straight-from-the-oven craveworthy satisfaction.
- Egyptian Aubergine Moussaka: Layers of roasted aubergine in a fragrant spiced tomato sauce — rich, hearty, and full of warmth.
- Mediterranean Gnocchi Bake: A one-pan gnocchi bake with tomatoes, mushrooms, prosciutto and cheese — simple, comforting, and bursting with sunny Mediterranean flavour.
- Mediterranean Potato Bake: Inspired by Pasta Puttanesca, this bake layers potatoes with olives, anchovies, and tomatoes for bold, vibrant Italian flavours in every bite.
- Baked Penne with Mushrooms and Spinach: Creamy and nourishing, this pasta bake combines earthy mushrooms and spinach in a dish that’s pure weeknight comfort.
Or try my absolute favourite way to cook spaghetti squash: this Baked Spaghetti Squash with Feta and Tomatoes. It’s simple, fresh, and oh so delicious!
Spaghetti Squash Casserole
This spaghetti squash casserole is a low-carb bake made with oven-roasted spaghetti squash, a savoury tomato-meat sauce, and a golden, cheesy topping. A comforting, easy, and family-friendly main dish.
I’d love your feedback – just click on the stars to rate this recipe! ⭐
Ingredients
- 1 spaghetti squash, halved lengthwise and seeds removed (1.2–1.4 kg)
- olive oil, for roasting and sautéing
- 400 g lean ground beef
- 1 small yellow onion, diced
- 2 garlic cloves, minced
- 1 tablespoon tomato paste
- 2 teaspoons Italian seasoning
- ½ teaspoon crushed red pepper flakes (optional, adjust to taste)
- sea salt and freshly ground black pepper, to taste
- 1 × 400 g can crushed tomatoes (or passata)
- 100 g young Gouda cheese, shredded
- 2–3 tablespoons freshly grated Parmesan cheese
- Fresh parsley or basil, to garnish
Method
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Roast the spaghetti squash: Preheat the oven to 200°C / 400°F (180°C fan-assisted) and line a baking sheet with parchment paper. Drizzle the cut sides of the squash with olive oil, place cut-side down on the prepared baking sheet. Roast until lightly browned on the outside, fork tender, but still a little bit firm (40 to 50 minutes, depending on the size of the squash).
TIP: It’s cooked when it gives slightly when you push on the outside. Do not overcook, as the strands should stay distinct and slightly firm rather than watery and mushy.
TIP: For a faster method: place squash halves in a microwave-safe dish with a little water and microwave on high for about 10 minutes, until tender.
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Sauté the aromatics: Heat a drizzle of olive oil in a large ovenproof skillet (Ø 26-28 cm) over medium heat. Add the onion and garlic; sauté until fragrant, about 2 minutes.
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Brown the meat: Add the ground beef and cook, breaking it up with a spoon, until browned.
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Build the flavour: Stir in tomato paste, Italian seasoning, red pepper flakes, salt, and pepper. Cook for 1 minute, then add the crushed tomatoes. Bring to a gentle boil, then reduce heat to simmer.
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Combine and bake: Use a fork to scrape the spaghetti-like strands from the cooked squash shells. Stir the squash into the sauce until well combined. Top with the shredded Gouda and Parmesan cheese.
TIP: If you don't have an ovenproof pan, you can transfer everything to a baking dish and sprinkle the cheese on top before baking.
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Bake and serve: Transfer the pan to the oven and bake until bubbling, about 15 minutes. Let stand for 5 minutes before serving. Garnish with fresh parsley or basil. Serve and enjoy!
Notes
- If your squash seems overly watery after roasting, toss the strands in a colander for a few minutes. It’s a small step, but it makes a big difference.
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