Butternut Squash Casserole With Cheesy Topping

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Butternut squash casserole with cheesy topping is full of cozy, fall flavors! It’s layered with sweet butternut squash cubes, chunks of sweet apple, Italian sausage, fresh herbs, fennel, and a delicious cheesy topping.

You’re sure to love this butternut squash casserole recipe! It’s perfect for the holiday season, whether you want to add some variety to the green bean casserole and cranberry sauce at your holiday table or you want to serve it as the main dish for a hearty weeknight dinner. All of my family members agree that this delicious fall recipe must be made on repeat.  

Squash is a long-time, personal favorite of mine. It’s like a warm, sweet hug reminiscent of my childhood. Growing up, I thought brown sugar and butter were the perfect combination with squash. Little did I realize how much I was missing. While it’s still one of my favorites, I discovered that squash pairs with so many other flavors.

Since then, my squash recipes have expanded to include butternut squash soup, stuffed butternut squash, and roasted squash fall salad. ​Its delicious flavor can be layered with many sweet and savory pairings, making it a fall kitchen staple.

This butternut squash dish is no exception. It has the sweet and savory combination of the sweetness of the butternut squash and apple, contrasting with the savory herbs, onion, fennel, and sausage, highlighting the best of fall.

What Is Butternut Squash?

Butternut squash is a medium-sized winter squash that weighs 3 to 5 pounds. Known for its bottle-like shape, the skin is dull tan, with a bright orange dense flesh that’s sweet and creamy when cooked.

Its sweet, nutty flavor is delicious when roasted whole or diced, but it can also be steamed, simmered, or grilled.

Equipment

• 9 x 13 baking dish or casserole dish
• Cutting board
• Sharp knife
• Large mixing bowl
• Large skillet 
• Baking sheet
• Parchment paper

Butternut Squash Casserole Ingredients

• Butternut squash: Peel and cube whole squash into small, uniform pieces for the best results. 
• Fennel – Look for firm, heavy bulbs without any browning or blemishes. I like to save the fronds to garnish the dish.
• Apple – Use a sweet apple that will hold its shape when it roasts. My favorite is Honeycrisp, but other good options are Golden Delicious, Braeburn, or Pink Lady. 
• Onion – Use white, yellow, or sweet onion.
• Herbs- Using fresh herbs are the best way to add flavor to any meal. The savory squash casserole uses fresh sage leaves, thyme, and rosemary.
• Maple syrup – Adds a touch of sweetness that complements the squash.
• Olive oil – Use any neutral oil like avocado or fractionated coconut oil. I suggest staying away from seed oils like corn, vegetable, or peanut oil.
• Cheese- Use gruyere and white cheddar together for a nice, smooth melt and unbeatable flavor.

How to Make Butternut Squash Casserole

Prep 

First, preheat the oven to 425 degrees.

Next, line a baking sheet with parchment paper.

Coat the 9 x 13 baking pan with a teaspoon of the olive oil and set aside. 

Peel the butternut squash. I’ve found the best way to peel the squash is with a vegetable peeler. Cut the squash in half from top to bottom with a sharp knife and scoop out the seeds with a spoon (save the seeds and roast them just like pumpkin seeds for a yummy snack). Place the squash on the cutting board, cut side down for stability, and cut into 1-inch cubes. 

Peel the cut the apple into similar size cubes. 

Mince the herbs finely and add to a large bowl along with the cubed butternut squash and apple chunks. Add 2 tbsp olive oil, 2 tbsp maple syrup, 1/2 tsp each minced rosemary, thyme, sage, and salt, and 1/4 tsp black pepper; toss to coat. 

Cook

Turn the squash mixture out onto the prepared baking sheet. Place it in the preheated oven and roast for 30-35 minutes, flipping halfway through, until the squash and apple pieces are tender. 

While the squash and apples roast, prepare the sausage. Place a large skillet, like cast iron, onto the stove over medium-high heat and add 1 tbsp of olive oil. Crumble the Italian sausage into the pan and cook until brown. Then, remove from the pan and add to a heat-proof, medium bowl.

There should be some fat remaining in the pan from the sausage, but if there isn’t, add a drizzle (1 tbsp) of olive oil to the pan. Dice the onion and fennel into small pieces and add to the cast iron pan. Sautee for 10-12 minutes over medium heat until soft and starting to brown. Turn off the heat, remove from the pan, and add to the bowl with the sausage; toss to combine. 

Assemble

Remove the squash and apples from the oven when they’re tender and set the oven to broil. 

Combine the casserole by gently spooning the roasted butternut squash and apples into the prepared baking dish. They’re soft, so be gentle handling so you don’t mash them.

Layer the sausage, fennel, and, onion mixture over the squash and apples. Using a wooden spoon, carefully lift the squash and apples a bit, letting the sausage, onion, and fennel fall amid the squash and apple chunks.

Shred the cheddar and gruyere cheese and sprinkle over the top of the casserole. Finish the casserole by placing it under the broiler for 2 or 3 minutes, or until the cheese is just starting to melt.

Garnish with additional chopped herbs or fennel fronds.

Store

Allow the casserole to cool completely to room temperature before placing the leftover butternut squash casserole into an airtight container. Refrigerate for up to 5 days. 

Tips

• Use pre-cut butternut squash to save on prep time. You can often find packages of cubed butternut squash in most grocery stores in the fall and early winter.
• Swap out the gruyere and white cheddar for your favorite type of cheese. Mozzarella, Monterey, brie, or parmesan cheese are excellent choices.