Butternut Squash Casserole Recipe

There is something truly magical about a warm, comforting dish that perfectly balances sweet and savory flavors, and my Butternut Squash Casserole does exactly that. This casserole combines silky roasted butternut squash and crisp Honeycrisp apples with fragrant herbs, caramelized fennel and onion, and house-made sweet Italian sausage all topped with gooey, golden Gruyere cheese. It’s a celebration of fall’s best flavors in one gorgeous, cozy bake that’s guaranteed to become a go-to favorite for family dinners and special gatherings alike.

Ingredients You’ll Need

Getting the ingredients right for this Butternut Squash Casserole is simple but essential. Each ingredient plays a starring role, from the sweet-tart Honeycrisp apples that add brightness to the earthy squash, to the aromatic herbs and silky Gruyere cheese that bring everything together with the perfect harmony of flavors and textures.

• Butternut squash, 2 pounds: Peeled and cubed, this is the hearty, creamy base of the casserole.
• Honeycrisp apples, 2: Peeled, cored, and cubed larger than the squash to provide a juicy, crisp sweetness.
• Olive oil: The perfect fat for roasting and caramelizing that adds richness without overpowering.
• Salt and black pepper: Essential seasonings to enhance all the natural flavors in the dish.
• Pure maple syrup, 2 tablespoons: Adds a gentle, sweet glaze that ties together the fruit and savory ingredients.
• Ground dried sage, 1/2 teaspoon: Brings a subtle earthiness that complements the savory and sweet notes.
• Herbes de Provence, 1 1/2 teaspoons: A fragrant blend of herbs to lift the flavor profile beautifully.
• Sweet Italian sausage, 1/2 pound: Casings removed and crumbled for a savory, juicy meat element.
• Fennel bulbs, 2 small: Thinly sliced and caramelized, they add delicate anise notes and a tender bite.
• Onion, 1 medium: Quartered, sliced, and caramelized with fennel for depth and sweetness.
• Gruyere cheese, 1 cup grated: Melts into a luscious, nutty topping that is irresistibly golden and gooey.
• Fresh sage leaves: For garnish, either fried crispy or fresh to add a bright herbal finish.

How to Make Butternut Squash Casserole

Step 1: Roast the Butternut Squash and Apples

Start by preheating your oven to 425°. Toss the cubed butternut squash and apples with olive oil, salt, black pepper, maple syrup, dried sage, and Herbes de Provence. Spread this buttery mixture on a foil-lined baking sheet and roast until tender and caramelized, about 35 minutes. This roasting step transforms both squash and apples, unlocking natural sweetness and a luscious creamy texture that is the heart of the casserole.

Step 2: Cook the Sausage

While the squash roasts, heat a drizzle of olive oil in a large skillet over medium-high heat. Add the crumbled sweet Italian sausage and cook until nicely browned and cooked through, about a few minutes. The savory sausage adds richness and a burst of flavor that balances the sweeter elements of the dish wonderfully.

Step 3: Caramelize the Fennel and Onion

In the same pan (adding a touch more olive oil if needed), add thinly sliced fennel and onion. Allow them to cook slowly over medium heat until deeply golden and jammy—this process unlocks their natural sweetness and a gentle complexity that complements both the sausage and the roasted squash beautifully.

Step 4: Combine All Ingredients

Once the squash and apples are tender, transfer them to a large bowl and add the cooked sausage, fennel, and onion. Pour in the remaining maple syrup and season with additional salt and pepper if needed. Toss everything gently so all flavors meld together. The result is an irresistible sweet-savory mixture ready to go into your casserole dish.

Step 5: Top with Gruyere and Broil

Spread the combined mixture in a 9-by-13-inch baking dish and sprinkle the grated Gruyere cheese evenly on top. Set your oven to broil and place the casserole under the heat just long enough to melt and golden the cheese to bubbly perfection. This final step adds a beautiful browned crust that makes each bite extra special.

Step 6: Garnish and Serve

For an elegant touch, fry fresh sage leaves quickly in hot oil until crisp, then drain and sprinkle lightly with salt. Scatter these on top of your Butternut Squash Casserole before serving, or simply sprinkle fresh sage leaves if you prefer. The fragrant, crispy sage pairs perfectly with the casserole’s warm flavors.

How to Serve Butternut Squash Casserole

Garnishes

The finishing touch of crispy fried sage leaves adds incredible aroma and a delightful textural contrast, while fresh sage leaves offer a bright herbal note that wakes up the dish. Either way, garnishing your Butternut Squash Casserole elevates it from delicious to absolutely memorable.

Side Dishes

This casserole is fantastic on its own but pairs beautifully with fresh green salads, crusty artisan bread, or simple roasted vegetables to round out a meal. Its rich, sweet-savory flavor works wonderfully alongside lighter, vibrant sides to make a balanced dinner.

Creative Ways to Present

For a beautiful presentation, serve your Butternut Squash Casserole in a rustic ceramic dish or individual ramekins for intimate dinners. You can also add a dollop of tangy crème fraîche or a sprinkle of toasted nuts on top for extra texture and flavor layers. It’s versatile enough to impress at cozy family dinners or chic holiday gatherings.

Make Ahead and Storage

Storing Leftovers

Once cooled, cover your Butternut Squash Casserole tightly and store it in the refrigerator for up to 3 days. The flavors meld and deepen overnight, making leftovers just as delightful, if not better, than freshly baked.

Freezing

This casserole freezes beautifully. Assemble the entire dish but skip the final broiling step; cover it tightly with foil or plastic wrap and freeze for up to 2 months. When ready to enjoy, thaw overnight in the fridge and then broil as directed until bubbly and golden.

Reheating

Reheat leftovers in a 350° oven covered with foil to prevent drying, about 15-20 minutes, then uncover and broil briefly to refresh the golden cheese topping. This approach keeps the texture and flavors vibrant, making each bite just as inviting as when first baked.

FAQs

Can I make this Butternut Squash Casserole vegetarian?

Absolutely. Simply omit the sweet Italian sausage and add extra caramelized fennel, mushrooms, or roasted nuts for a satisfying vegetarian twist that maintains rich flavor and texture.

What can I substitute for Gruyere cheese?

If Gruyere isn’t available, Swiss or Fontina cheese make good alternatives. They melt well and have a similar nutty flavor that complements the sweet and savory elements of the casserole.

Is it okay to prep this casserole ahead of time?

Yes! You can prepare the roasted squash, caramelized vegetables, and sausage mixture a day in advance, then assemble and broil the casserole right before serving to save time on busy days.

Can I use canned butternut squash instead of fresh?

Fresh is best for texture and flavor, but if using canned, drain it well and roast briefly to remove excess moisture and deepen the flavor before using it in the casserole.

What wine pairs well with Butternut Squash Casserole?

A lightly oaked Chardonnay or a fruity Pinot Noir work wonderfully, as their balance of acidity and fruitiness pairs nicely with the sweet, earthy, and savory flavors of the dish.

Final Thoughts

This Butternut Squash Casserole is truly one of those dishes you’ll find yourself craving again and again. It’s cozy, flavorful, and surprisingly easy to prepare, making it perfect for both weeknight dinners and holiday celebrations. I can’t wait for you to enjoy this heartwarming recipe that turns humble ingredients into something extraordinary. Give it a go—you might just discover your new favorite way to celebrate autumn’s bounty!

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