Creamy Cauliflower Spaghetti Squash Casserole

This Creamy Cauliflower Spaghetti Squash Casserole doesn’t make sense in the BEST way. The velvety cauliflower cream sauce, gooey melted cheese, hearty ground turkey, and tender strands of spaghetti squash make it comforting and indulgent, but the macros? Next level. With basic ingredients, literally one pan, and room for dessert, you already know this one’s a keeper!

About This Recipe

There was a day when I thought I’d never make something called a casserole. Remember when it meant emptying lots of cans into a dish and calling it dinner? Not the biggest fan of that. But lots of healthy food packed into one dish that comes out of the oven to feed everyone at once without being surrounded by a blown-up kitchen? That I can get behind.

But you know what’s crazier than the ease and yumminess of this cauliflower spaghetti squash casserole? THE MACROS. Insane. This is a huge pan, and I calculated a serving at about 1/4th of it, which is 400g. And it’s less than 300 calories. Which means a full belly PLUS a bigger dessert, and I KNOW how you feel about that.

I made this casserole with leftover cauliflower cream sauce from my Chicken Divan recipe, and guys… it’s a must! Making a fresh batch will work too, and I’ve got a substitution for you down in the recipe card if you need it!

If you love a cozy, macro-friendly casserole that’s high in protein, low in fat and carbs, high in taste and VOLUME, you’ll find lots more recipes like this one in my One-dish meal cookbook!

Here’s What Others Think

“Absolutely amazing! Extremely flavorful with the best macros – so fulfilling!! Definitely worth making the cauliflower sauce – it’s really not too much work, it’s super easy if you follow her shortcuts.” – Alejandra

Ingredients and Substitutions

• Extra lean ground turkey if you want the superhero macros. Just use regular ground turkey if you’re ok with great macros. Beef if you don’t care. Italian sausage if you’re really living on the edge… we could go on!
• Can of tomatoes: Adds that rich, saucy base that ties everything together.
• Fresh spinach: Wilts right into the dish without overpowering it. Kale or arugula work just as well if that’s what you have on hand. Great source of fiber!
• Cauliflower cream sauce: I highly recommend using my homemade cauliflower cream sauce (recipe below), but you could sub in an equal amount of your favorite jarred marinara, and the macros will not be that different. Of course, the whole dish would be more tomatoey, but I’m sure it’d be great!
• Fresh basil: A handful of this at the end makes everything taste brighter and fresher. Don’t skip it if you can help it!
• Spaghetti squash: This summer squash keeps things light and low-carb while still giving you that satisfying, noodle-like texture.
• Mozzarella cheese: That golden, bubbly top layer is everything. I use regular part-skim, NOT low-fat– it’s so light, I figured it could afford a little bit of real cheese flavor! But feel free to sub in what you want.

Dietary Adaptations 

GF/DF: This recipe is naturally gluten-free, but double-check the label on your canned tomatoes, since some brands sneak in gluten-based thickeners or seasoning blends. To make things dairy-free, swap the mozzarella for your favorite dairy-free shredded cheese (it may not get quite as melty, but it’ll still add that cheesy top), and swap the cauliflower cream sauce with jarred marinara instead.

How to Make

1. Cook your spaghetti squash however you like. You can roast it cut side down like Martha Stewart, which is my preferred method. Or just poke it a few times and put the spaghetti squash in the microwave for 5-8 minutes, which is what I did for this! While it’s cooking, continue with the rest of the steps.
2. Next, heat a heavy-bottomed shallow pan over medium-high heat. Spray with cooking spray and add diced onions and a sprinkle of kosher salt. Cook for 3-4 minutes, until tender.
3. Add ground turkey and seasonings. Once the ground turkey is chopped up and cooked through, you can add more salt to taste if needed.
4. Add drained tomatoes and garlic. Cook for another 3 minutes. Then add chopped spinach and mix it in, letting it cook for a couple of minutes to wilt and get nice and mixed in.
5. Now stir in 400g of cauliflower cream sauce and the fresh basil (it looks ugly now, but it’s gonna be ok!)
6. Carefully cut the squash in half lengthwise, scoop out seeds and insides with an ice cream scoop, careful not to pull out too much of the good stuff.
7. Using a fork, scrape the squash into strings to get them all loose from the skin and add them to the ground turkey mixture. Mix it all together well in the pan with tongs.
8. If you’re using an oven-safe pan, smooth the top of the mixture and top with mozzarella. Bake at 350°F for 15-20 minutes till the top is melty and bubbly. If you want it to brown a bit like mine, broil for an additional 3-5 minutes. But watch it closely so it doesn’t burn!
9. If it’s not an oven-safe pan, transfer the mixture to a casserole dish, top with cheese, and bake as described.

How To Store For Later

Store your leftover cauliflower spaghetti squash casserole in an airtight container in the fridge. Make sure it’s completely cooled before you seal it up, and it should stay fresh and tasty for up to 3 to 5 days.

Helpful Tips

• I recommend making this dish when you’ve ALREADY made a batch of the cauliflower cream sauce because then you can really just dirty the one dish!
• When browning the ground turkey, resist the urge to stir it too much. Let it sit for a minute so it gets a little color, which adds a ton of flavor.
• I like to taste the turkey mixture before adding the cauliflower cream sauce so I can adjust the seasoning first. It’s much easier to tweak at that stage.
• If your pan isn’t oven-safe, just use a 9×13 casserole dish. It works just as well and is super easy to clean up.
• I find tongs are the best tool for mixing the squash strings into the turkey mixture. They give you way more control than a spoon.