Butternut Squash Breakfast Casserole With Sausage

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This Butternut Squash Breakfast Casserole made with eggs, lean turkey sausage, butternut squash, spinach, and red onion is a filling and nutritious breakfast that is great for meal prep. Easy to make and full of flavor.

331 CAL 12g CARBS 16g FAT 33g PROTEIN

This hearty Butternut Squash and Egg Breakfast Casserole will feed a crowd! It's made with all whole ingredients including butternut squash, turkey sausage, and fresh spinach for a hearty breakfast that is as nutritious as it is delicious.

Sausage and butternut squash has been one of my favorite combinations for a long time. Usually, when I pair the two, it is in a simple hash. But lately, I have been making lots of egg casseroles for breakfast during the week, and my beloved squash and sausage are the perfect combination.

Not only is it packed with protein, but it's also extremely filling. It will keep you going all morning. I like to add spinach to mine for some greens as well as red onion. You could also add bell peppers, mushrooms, and no one would blame you if you threw some cheese on top.

Butternut squash lovers also won't want to miss these tasty Butternut Squash Tacos.

Egg casserole with butternut squash and spinach in a dish with a fork and knife on the side.

Key Ingredients For Butternut Squash Breakfast Casserole

This casserole is packed with heart-healthy and fiber-rich whole ingredients. I don't usually like to follow diet trends, but it does qualify as Whole30 compliant. That means that all the ingredients are whole foods without any added sugars of any sort (and no dairy either).

Here's a little bit more information about the ingredients I used:

  • Turkey Sausage: I used lean ground turkey sausage because it's a leaner meat than pork. If you want to use pork sausage, I suggest staying away from any that has added syrups or sugar in it.
  • Olive Oil: You can substitute olive oil with avocado oil or even coconut oil. Some people that are following a dairy-free diet might want to use ghee.
  • Onion: I think that red onion has the best flavor in this casserole. You could also use white or yellow onion instead.
  • Salt And Pepper: Only use as much as you need to give it a little extra taste.
  • Spices: For the dried herbs, I used garlic powder and oregano, but you could also sprinkle in some parsley. I love how it brings out the sweeter notes in the butternut squash.
  • Butternut Squash: Peel and dice it. You might even be able to find peeled and diced butternut squash in the frozen food section.
  • Eggs: You will need both the eggs and the egg whites.

Note: For a full list of ingredients and detailed instructions on how to make this breakfast casserole, take a look at the printable recipe card at the bottom of this post! 

What To Serve With Sausage Squash Casserole

This is a very hearty casserole that tastes amazing all by itself. It has vegetables, eggs, and sausage - it's an entire meal.

On the side, you could serve some applesauce oatmeal muffins for some gut-healthy fiber. If you have a sweet tooth, then make some blueberry oatmeal muffins instead. Both choices are incredibly popular with groups and take almost no time to make.

Recipe Tips And Ideas For Squash And Sausage Casserole

Follow these tips to make sure the casserole comes out perfectly every single time.

  • Always preheat your oven while you prep the rest of the ingredients. Your casserole will bake so much better if you put it into a preheated oven.
  • Chop the butternut squash up evenly. To save yourself time, you can also choose to use frozen diced butternut squash. If you use frozen, let it thaw and then pat it dry so it doesn't turn mushy in the bake.
  • If your oil is spitting at you while you saute the squash and onion, turn the heat down. You can also add a bit of water if you notice things start to burn.
  • Spray your cooking dish with cooking spray before you add the casserole ingredients to it. This recipe tends to stick to most dishes.
  • You could also turn this recipe into breakfast muffins. Just pour the ingredients into a prepared muffin tin and bake for 30 minutes - or until a toothpick comes out clean.

Butternut squash, spinach, and sausage egg casserole with greens and avocado on the side.

Frequently Asked Questions

Here are some questions I frequently get asked about by some readers...

Can I use a different type of squash instead of butternut?

No, I do not suggest you try to use any other type of squash. Even though I am usually supportive of swapping ingredients, there really aren't any other types of squash with the same shape or texture as butternut. The only one that comes close is acorn squash.

You can use sweet potatoes in place of butternut squash - they take the same length of time to cook and have a very similar taste and texture.

When is butternut squash in season?

Butternut squash is available year-round. If you want to get it from your local farmer's market, you will have the most luck finding it early fall until the start of winter.

How can I sweeten butternut squash breakfast casserole?

If you want it to taste sweet, add a small bit (about a teaspoon) of honey to it before you bake it.

How do you store leftover casserole?

Store leftovers in an airtight container in the refrigerator. It will stay fresh for up to 5 days.

Egg breakfast casserole with sautéed butternut squash, spinach, sausage, and red onion in a baking dish.

More Breakfast Recipes You'll Love:

The Recipe
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Butternut Squash Breakfast Casserole With Sausage

331 CAL 12g CARBS 16g FAT 33g PROTEIN
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  • 1 lb. lean ground turkey sausage
  • 2 tsp. olive oil
  • 2 cups butternut squash, peeled and diced
  • 1/2 red onion, diced
  • 1/2 tsp. salt
  • 1/2 tsp. garlic powder
  • 1/2 tsp. oregano
  • 1/2 tsp. pepper
  • 4 cups spinach, chopped
  • 4 eggs
  • 4 egg whites

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Preheat the oven to 400 degrees. Heat a skillet over medium high heat. Add the sausage and cook until no longer pink, breaking it up as it cooks. Remove and set aside.

Ground turkey sausage browning in a skillet.

Add the olive oil to the pan. Once hot, add the butternut squash and red onion. Cook for 8-10 minutes until squash and onion are tender, adding 1-2 tablespoons of water if burning. Add the salt, garlic powder, oregano, and pepper. Stir together. Add the spinach and cook until it wilts, about 1-2 minutes.

Butternut squash, spinach, and red onion cooking in a skillet.

Whisk together the eggs. Add the sausage and butternut squash mixture to a baking dish sprayed with cooking spray. Pour the eggs over top.

Eggs being whisked in a bowl.

Bake for 25-30 minutes until eggs set and are cooked through.

Butternut squash breakfast casserole cooking in a dish in the oven.
Nutritional Facts
Serving Size: 1 square
Amount Per Serving
Calories 331
Calories from Fat 148
% Daily Value *
Total Fat 16g
Saturated Fat 4g
Monounsaturated Fat 0g
Polyunsaturated Fat 0g
Cholesterol 271mg
Sodium 1120mg
Total Carbohydrate 12g
Dietary Fiber 3g
Sugars 3g
Protein 33g

* Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.

The Nutritional Values provided are estimates only and may vary based on the preparation method.

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About the author Meet Kristen McCaffrey
Hi, I’m the cookbook author, recipe developer, and food enthusiast behind Slender Kitchen. I am obsessed with making healthy food that is easy to prepare and absolutely delicious. Meal planning is my secret weapon and I hope I can make meal time easier for you with our tried and tested recipes and foolproof meal plans. Learn More
On Butternut Squash Breakfast Casserole With Sausage
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Joseph Kidd
September 26, 2021 - 12:50
How many servings does it make?
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September 28, 2021 - 15:57
It makes four servings.
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Joseph Kidd
September 26, 2021 - 12:50
How many servings does it make?
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Deanna Fitzpatrick
July 30, 2020 - 08:01
Add a Rating:
This recipe is delicious. I love getting vegetable servings in for breakfast. If cutting up the vegetables feels daunting, I found that I could buy frozen butternut squash already diced in perfect little squares. Plus, one package is 2 cups! Perfect!
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September 18, 2018 - 12:56
Could I prep this the night before?
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Deanna Fitzpatrick
July 30, 2020 - 08:02
Yes, it's really good reheated.
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Margie Hayes
January 8, 2018 - 09:29
Add a Rating:
I just joined and this was the first recipe I made. It turned out great. I used my 10 inch round cast iron skillet. Was tasty and filling. Looking forward to trying more recipes.
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