If you’re looking for a cozy, crowd-pleasing dish that captures the spirit of fall in every bite, this Butternut Squash Casserole checks all the boxes. Bursting with tender roasted butternut squash and sweet Honeycrisp apples, enriched with aromatic herbs and savory Italian sausage, it’s a beautiful blend of sweet, savory, and cheesy goodness. The final touch of melted Gruyere cheese and a sprinkle of fresh or crispy fried sage takes this casserole from delicious to downright unforgettable. Trust me, once you make this Butternut Squash Casserole, it’ll become your seasonal favorite too!

Butternut Squash Casserole Recipe - Recipe Image

Ingredients You’ll Need

This recipe comes together with simple, wholesome ingredients that each bring something special to the table. Whether it’s the sweetness of the apples and maple syrup, the hearty savoriness of the sausage, or the aromatic herbs that tie it all together, these ingredients work in harmony to create a comforting texture and vibrant flavor profile.

Butternut squash (2 pounds): Peeled and cubed, this is the star ingredient lending creamy sweetness and a velvety texture.

Honeycrisp apples (2): Peeled, cored, and cubed, their crisp and sweet qualities perfectly complement the squash.
Olive oil: Used for roasting and sautéing to bring out the natural flavors with a subtle fruity richness.

Salt: Balances and enhances all the flavors in the dish.
Black pepper: Adds a gentle mild heat and depth to the casserole.

Pure maple syrup (2 tablespoons): Half used in roasting, half stirred in later for a natural sweetness that ties ingredients together.
Dried ground sage (1/2 teaspoon): Infuses that signature earthy, herbaceous note that’s perfect with squash and sausage.
Herbes de Provence (1 1/2 teaspoons): A fragrant mix that brightens the flavor with floral and savory hints.

Sweet Italian sausage (1/2 pound): Casings removed and crumbled to bring savory richness and a meaty bite.
Fennel bulbs (2 small): Thinly sliced for sweetness and a slight anise aroma that balances the dish beautifully.
Onion (1): Quartered and thinly sliced, caramelized to add a deep, jammy sweetness.

Gruyere cheese (1 cup grated): For that irresistible melty, nutty topping that blankets the casserole.
Fresh sage leaves: Optional fresh or fried for garnish, adding a lovely herbal crunch or fresh brightness.

How to Make Butternut Squash Casserole

Step 1: Roast the Butternut Squash and Apples

Start by preheating your oven to a toasty 425 degrees and lining a baking sheet with foil for easy cleanup. Toss the butternut squash and apples in olive oil, salt, pepper, half the maple syrup, dried sage, and Herbes de Provence. Make sure everything is evenly coated — this step really sets the foundation for the casserole’s deep flavors. Spread them out on the sheet and roast for about 35 minutes, giving them a good stir occasionally so they brown evenly and develop that lovely roasted sweetness.

Step 2: Cook the Sausage

While your squash and apples are roasting, heat a drizzle of olive oil in a large skillet over medium-high heat. Add the crumbled sweet Italian sausage and cook until it’s beautifully browned and cooked through. This savory sausage adds a fantastic heartiness and meaty flavor that contrasts gorgeously with the sweetness of the veggies.

Step 3: Caramelize Fennel and Onion

In the same skillet, add a bit more olive oil if needed and toss in the thinly sliced fennel and onion. Cook them low and slow until they turn a deep golden color and get deliciously jammy — this will take about 10 to 12 minutes. The caramelized fennel and onion bring layers of sweetness and aroma that elevate every bite of the casserole.

Step 4: Combine and Prepare for Baking

Once the roasted squash and apples are tender and ready, turn your oven to the broil setting. Transfer the roasted mixture into a large bowl and mix in the sausage-fennel-onion blend. Pour in the remaining maple syrup and toss everything together, seasoning further with salt and pepper if you like. Then, spoon this delicious mixture into a medium-sized baking dish to get ready for the cheesy finish.

Step 5: Add Cheese and Broil

Top the assembled casserole with grated Gruyere, making sure it’s distributed evenly to create that golden, bubbly crust. Place under the broiler for just a few minutes until the cheese melts beautifully and takes on a mouthwatering golden brown color. Keep a close eye so it doesn’t burn!

Step 6: Garnish and Serve

If you’re feeling fancy, fry some fresh sage leaves quickly in shimmering oil until crisp for a wonderful crunchy garnish. Otherwise, fresh sage leaves make a lovely herbaceous topping that brightens the whole dish. Sprinkle them on just before serving and get ready to dive into a plateful of comforting goodness.

How to Serve Butternut Squash Casserole

Garnishes

The garnish can make all the difference. Crispy fried sage leaves add an addictive crunch and herbal depth, while fresh sage sprigs offer an aromatic freshness and rustic beauty. Either choice perfectly complements the Butternut Squash Casserole’s rich, layered flavors.

Side Dishes

This casserole shines as a hearty side or main dish. Pair it with simple roasted Brussels sprouts or a crisp green salad for contrast. Or serve alongside a roasted turkey or chicken for a memorable holiday or family dinner. Creamy mashed potatoes or crusty bread also work well to soak up any extra savory goodness.

Creative Ways to Present

For a charming touch, serve the Butternut Squash Casserole in individual ramekins topped with a single fried sage leaf. Alternatively, layer it in a glass casserole dish to show off the vibrant orange squash, golden cheese, and caramelized veggies. This makes for a stunning centerpiece that invites guests to dig right in.

Make Ahead and Storage

Storing Leftovers

Leftover Butternut Squash Casserole keeps beautifully in an airtight container in the refrigerator for up to 3 days. The flavors even deepen with a bit of resting time, making it a fantastic next-day meal or snack.

Freezing

If you want to save some for later, this casserole freezes wonderfully. After baking and cooling completely, wrap tightly with foil or place in a freezer-safe container. It will keep well for up to 2 months. Just thaw overnight in the fridge before reheating.

Reheating

Reheat your Butternut Squash Casserole covered in a 350-degree oven until warmed through, about 20 to 25 minutes. To revive that cheesy crust, remove the cover near the end and broil for a couple of minutes. Microwaving also works for quicker reheats but may soften the topping.

FAQs

Can I make this casserole vegetarian?

Absolutely! You can simply omit the sweet Italian sausage and add extra vegetables like mushrooms or roasted chickpeas for protein. Consider boosting the flavors with a splash of soy sauce or smoked paprika to maintain that savory punch.

What can I substitute for Gruyere cheese?

If Gruyere isn’t available, you can use Swiss cheese or even mozzarella for melting. Parmesan mixed with mozzarella also yields a nice nutty, gooey topping, though it won’t have the exact same buttery flavor as Gruyere.

Is it okay to use frozen butternut squash?

While fresh butternut squash provides the best texture and flavor, you can use frozen squash in a pinch. Just thaw and drain any excess moisture well before roasting to avoid a watery casserole.

Can I prepare this casserole vegan?

To veganize the Butternut Squash Casserole, swap the sausage for plant-based sausage or seasoned lentils, use nutritional yeast or a vegan cheese alternative, and skip the maple syrup or use agave nectar. The fennel and herbs will still provide wonderful flavor.

How spicy is this casserole?

This recipe isn’t spicy at all — it leans into sweetness and savoriness with very mild pepper heat. You can add a pinch of crushed red pepper or cayenne if you want a little kick.

Final Thoughts

I can’t recommend this Butternut Squash Casserole enough if you want something that feels like a warm hug on a plate. It’s a perfect blend of sweet, savory, cheesy, and herbaceous, making it just right for cozy dinners or holiday meals. Once you give this recipe a try, I’m sure it’ll become a beloved staple in your cooking rotation too. Happy baking and even happier eating!

Butternut Squash Casserole Recipe

★★★★★

4.9 from 9 reviews

Author: lina
Total Time: 1 hour 5 minutes

Yield: 6 servings 1x
Diet: Halal

Print Recipe

Description

This Butternut Squash Casserole blends the natural sweetness of roasted butternut squash and Honeycrisp apples with savory Italian sausage, caramelized fennel and onion, and the nutty richness of Gruyere cheese. Enhanced with maple syrup, herbs like sage and Herbes de Provence, this comforting casserole is perfect for a cozy autumn meal or holiday gathering. The crispy, fragrant fried sage leaves add a delightful finishing touch.

Instructions

Preheat Oven and Prepare Baking Sheet: Preheat your oven to 425°F (220°C) and line a baking sheet with foil lightly misted with cooking spray to prevent sticking.
Toss Butternut Squash and Apples: In a large bowl, combine the cubed butternut squash and apples. Drizzle with about 2 tablespoons of olive oil, then season with salt, black pepper, 1 tablespoon maple syrup, dried sage, and Herbes de Provence. Toss well to evenly coat all pieces.

Roast Vegetables and Apples: Spread the squash and apple mixture evenly on the prepared baking sheet. Roast for approximately 35 minutes, stirring occasionally to ensure even caramelization, until the squash is tender and golden.
Cook Sausage: While roasting, heat a large skillet over medium-high heat with a small drizzle of olive oil. Add the crumbled Italian sausage and cook until browned and cooked through, about 4-5 minutes. Remove sausage from the pan and set aside.
Caramelize Fennel and Onion: In the same skillet, add more olive oil if needed. Add the thinly sliced fennel and onion, cooking over medium heat for about 10 to 12 minutes until deeply golden and jammy in texture. Remove from heat and combine with cooked sausage in a bowl.

Broiler Preparation: When the squash and apples are done roasting, switch the oven setting to broil to prepare for finishing the casserole.
Combine Ingredients: Carefully transfer the roasted squash and apples to a large bowl. Add the sausage, fennel, and onion mixture to the bowl. Pour in the remaining 1 tablespoon maple syrup and toss gently to blend all flavors. Adjust seasoning with additional salt and pepper as desired.
Assemble Casserole: Spoon the combined mixture into a 9 by 13-inch baking dish, spreading it out evenly.

Fry Sage Leaves (Optional Garnish): Heat about 1/4 cup olive oil in a small saucepan over medium heat until shimmering. Fry the fresh sage leaves for about 20 seconds until crisp, then remove and drain on paper towels. Sprinkle lightly with salt.
Broil with Cheese: Sprinkle the grated Gruyere cheese evenly over the casserole. Place under the broiler for a few minutes until the cheese melts and turns a golden-brown color. Watch closely to prevent burning.
Garnish and Serve: Garnish the casserole with the fried sage leaves or fresh sage leaves as preferred. Serve warm and enjoy this flavorful, comforting dish.

Notes

Use Honeycrisp apples for their crisp texture and balanced sweetness that complements the squash well.
Adjust maple syrup to taste depending on your preferred level of sweetness.
To keep the dish gluten-free, verify that Italian sausage contains no gluten additives.

If you prefer a vegetarian version, omit sausage and add mushrooms or plant-based sausage.
Watch the casserole closely when broiling to avoid burning the cheese topping.
Fried sage leaves add a delightful crisp texture but can be skipped if desired.

Prep Time: 20 minutes
Cook Time: 45 minutes
Category: Casserole

Method: Roasting, Sautéing, Broiling
Cuisine: American

Nutrition

Serving Size: 1 cup

Calories: 320 kcal
Sugar: 10 g
Sodium: 480 mg

Fat: 18 g
Saturated Fat: 6 g
Unsaturated Fat: 10 g

Trans Fat: 0 g
Carbohydrates: 25 g
Fiber: 4 g

Protein: 12 g
Cholesterol: 45 mg

Keywords: butternut squash casserole, roasted squash, Italian sausage casserole, fall recipes, autumn side dish, maple and sage casserole