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Sweet Butternut Squash Casserole Recipe

Sweet and savory, nutty and crunchy, this delicious Keto Butternut Squash Casserole has everything you’re looking for in a perfect Fall side dish! 

Butternut Squash Casserole on a spoon

Because we have entered into the most wonderful season of all….it’s Fall in case you guys don’t know that about me yet. We have so many recipes that are just so perfect for fall time.

We’ve already talked about a few of my favorites such as Butternut Squash Soup, Pumpkin Pie, “Apple” Crisp, Pumpkin Chocolate Chip Cookies, “Apple” Pie, that now it’s time we discuss Butternut Squash Casserole.  

This recipe is actually from one of my really good friends. She’s been making this for me for years and it was one of the first things I learned how to make on my own when I learned to cook.

Her recipe isn’t exactly keto, but that’s ok. I was able to make some minor tweaks to the recipe and now we have a super delicious butternut squash casserole that’s 100% keto-friendly. 

Some of you might feel that most butternut squash casseroles you’ve ever had have been savory. This one is not only savory but has a sweet crunchy topping, a perfect combo! 

Can you Eat Butternut Squash on Keto?

Technically butternut squash is not really on the keto-approved list, because it’s considered to be starchy vegetable. On its own, it’s not really suitable for a keto lifestyle.

That being said, it doesn’t mean you can’t fit some butternut squash into your low carb or keto diet. 

I don’t recommend eating butternut squash in large quantities, but thankfully with this low carb butternut squash casserole all you need is ½ cup serving and you will be all set!  

What Ingredients are in Butternut Squash Casserole?

Keto Butternut Squash Casserole ingredients

Butternut Squash – The main ingredient of this recipe. I usually will tell you to roast your squash, but with this particular recipe, I actually boil mine on the stove. Butternut squash is ALWAYS better if it’s fresh.

Butter – A mandatory ingredient in order to make the yummy crunchy topping. But if you need this to be dairy-free, then substitute it with dairy-free butter, such as Earth Balance. 

Low Carb Sweetener – Swerve Brown Sugar is what you absolutely need for this topping.  A regular white low carb sweetener won’t cut it for this recipe.

You need the molasses flavor that comes with brown sugar, and that comes out great in Swerve Brown Sugar.

Pecans & Walnuts – I chose to use a combo of both pecans and walnuts because I like using both. But you can just use one kind if you prefer, or you can use another nut entirely. 

How Many Carbs are in Low Carb Butternut Squash Casserole?

So like I have previously said, technically butternut squash isn’t one of the keto-approved vegetables. But for some of you out there, it’s something that can be added in small quantities. 

Plus it also contains butter, walnuts, pecans, and a low carb sweetener. All ingredients that are keto-approved. 

Even though large quantities of butternut squash alone may be too many carbs for you, a heaping ½ cup serving of this easy butternut squash casserole is only 6.8 NET CARBS. Not too bad at all!  

Is Butternut Squash Healthy?

Low Carb Butternut Squash Casserole

Even though butternut squash is gonna be higher in carbs than other vegetables, it doesn’t mean that it isn’t healthy. It’s the exact opposite actually, butternut squash is a very healthy vegetable. 

It’s versatile and is known for its sweet nutty flavor, it can be eaten raw, roasted, mashed or pureed.

Butternut squash is packed with fiber, antioxidants, minerals, and vitamins while being very low in calories. 

How to Make Butternut Squash Casserole

Start off by preheating the oven to 350 degrees

Now, get the walnuts and pecans out and chop them into small pieces. Grab a small bowl, and combine the softened butter, Swerve brown sugar, chopped pecans and walnuts.

Mix all the ingredients together. I find with this step sometimes it’s just easier to use your hands to mix, so dig in. 

Let’s get the butternut squash all ready to go.

Cut the top and bottom off, and while using a vegetable peeler start to peel the squash. Working from top to bottom with the peeler is the easiest way to do it. 

See our guide for the secret to cutting and peeling butternut squash if you really want to make things easy.

Freshly Cut Butternut Squash

Once it’s all peeled cut into chunks. Don’t worry about cutting them all the same size, they are getting mashed anyways. 

Once the squash is all cut up, throw it into a stockpot. I like to use a taller one because it’s easier to mash later on.

Butternut Squash in a pot

Fill the pot with water, covering the squash completely.

Butternut Squash in a pot with water

Turn it on to high heat and bring to a boil.

boiling Butternut Squash on the stove

Let the squash boil until it’s soft and you can poke it with a fork and it falls apart.

When you feel it’s now softened enough, drain the squash in the sink using a colander.

Butternut Squash freshly boiled

Dump the squash back into the stockpot once it’s been drained. 

Add 2 tbsp of butter, and using an electric mixer start mashing the butternut squash. Season with some salt and pepper. Transfer it to a baking dish. 

Now it’s time to add the topping. You should have enough topping to pretty much cover the all of the butternut squash. 

Bake it for about 30 minutes or until the top is golden brown and it starts to bubble.

Butternut Squash Casserole recipe

Additional Tips for Cooking Butternut Squash Casserole:

As I talked about already, I chose to boil my butternut squash simply for the reason that it was easier and 1 less dish to have to wash. But you can roast the butternut squash instead

  1. Just put the cut pieces of squash on a baking tray, drizzle with some olive oil and sprinkle with salt and pepper.
  2. Roast for about 20 minutes on 400 degrees.
  3. Once it’s soft, then you can mash it and follow all the other steps as listed. 

Different Ways to Make Butternut Squash Casserole

Keto Butternut Squash Casserole

If you aren’t following a low carb diet, then you can make this recipe the way my friend has always made it.

Instead of using a low carb brown sugar, you can use a regular light brown sugar, and also add 1 cup of crushed cornflakes. Mix all the topping ingredients together, and bake. 

Different herbs such as sage and thyme and spices like nutmeg and cinnamon go great with butternut squash. So adding any of these could be a nice different way to make a butternut squash casserole. 

If you are looking for some savory ideas, here’s a few things you could do: 

  • Fresh thyme, Prosciutto, Mozzarella, and Parmesan
  • Parmesan, Spinach, Smoked Paprika, Garlic, Thyme and Sage
  • Southwestern Casserole: Cayenne, nutmeg, parmesan, heavy cream, black pepper
  • Prosciutto, Leeks, Heavy Cream, and Fresh Thyme

Other Diets this Recipe is Good for:

This is not only keto, but it’s sugar-free and gluten-free as well. Using the Swerve Brown Sugar in replacement of regular brown sugar makes it completely sugar-free. 

Unfortunately, though my version isn’t dairy-free because I use butter. But it’s easily fixable. You can use a dairy-free butter substitute like Earth Balance, or another one of your choice if you want to go that way. 

If you choose to do it this way, then that would make this a great vegan option for you as well. 

What Can I Serve with Butternut Squash Casserole? 

Keto Butternut Squash Casserole in a dish

Oh man, what a question this is…I feel like the correct answer is pretty much anything goes with this low carb butternut squash casserole.

Typically this is the perfect side dish for a Turkey dinner. But honestly, you can serve it as a side dish for any meat dish. Here are some dishes that you can serve this easy low carb butternut squash casserole with: 

How to Store Butternut Squash Casserole 

All that’s needed to store this easy low carb casserole is some glass or plastic Tupperware. Place your leftover casserole in an airtight container and store in the fridge. It should last for 3-4 days in the fridge no problem. 

Can I Freeze Butternut Squash Casserole?

This is a perfect make-ahead recipe when you are on a time crunch. You can make it ahead of time and take the pressure off of yourself.

All you have to do is make the casserole, wrap it tightly in plastic wrap then foil. You can freeze it for up to 1 month. 

More Low Carb Fall Recipes

If you’re in the mood for some other Low Carb Autumn Recipes then try our:

They all are low carb, and will hit the spot on a nice Autumn day!

easy Butternut Squash Casserole
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Keto Butternut Squash Casserole recipe

Sweet Butternut Squash Casserole Recipe

  • Author: Stephanie Parlegreco
  • Total Time: 60 minutes
  • Yield: 14 servings (1/2 Cup per serving) 1x
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Sweet and savory, nutty and crunchy, this delicious Low Carb Butternut Squash recipe has everything you’re looking for!  It’s also very easy to make and healthy! 


  • 2 lbs butternut squash
  • 6 tbsp softened butter, (divided 4 tbsp and 2 tbsp)
  • ½ cup chopped pecans
  • ½ cup chopped walnuts
  • ½ cup Swerve Brown Sugar




Follow our Full Guide on How to Peel, Seed and Cut Butternut Squash

You can buy precut butternut squash if you don’t want to buy a whole one and have to peel and cut it. 

Roasting your squash is an option as well. Roast it in the oven at 425 degrees with olive oil drizzled on top. 

Adding cinnamon, nutmeg, sage, or thyme can be added to your squash. 

Store in the refrigerator for 3-4 days in a sealed container.

This can be prepared ahead of time and then frozen. Wrap the casserole in plastic wrap and then foil. Place in the freezer for up to 1 month. Thaw it out on the counter and then bake for 30 minutes. 

  • Prep Time: 30 minutes
  • Cook Time: 30 minutess
  • Category: Side Dishes
  • Method: Baking
  • Cuisine: American

Keywords: Butternut Squash Casserole, Keto Butternut Squash Casserole, Low Carb Butternut Squash Casserole, Butternut Squash Casserole Recipe, Keto Butternut Squash Casserole Recipe, Sweet Butternut Squash Casserole recipe, Best Butternut Squash Casserole, Easy Butternut Squash Casserole Recipe, Gluten-Free Butternut Squash Casserole Recipe, healthy Butternut Squash Casserole

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Tuesday 7th of September 2021

Can you freeze butternut squash? If so would you have to cook it first or just peel and deseed it.?

Leigh Oskwarek

Tuesday 7th of September 2021

Hi Dee, You can freeze butternut squash either raw or cooked. There are some good instructions online. Just google it and pick your favorite way to try it. You can buy a bunch when it's on sale and then freeze it.