This light, fluffy Butternut Squash Casserole makes a festive addition to any holiday table. Homemade butternut squash purée gives the filling a silky texture and fresh flavor, while a pecan-oat streusel adds a crunchy, comforting finish. The casserole can be prepped and assembled ahead of time so you can spend more moments with family and friends.
The holidays are here, and I love filling the season with simple comforts—cozy candles, warm mugs and meals made with seasonal produce. Butternut squash is a staple for me this time of year because it’s versatile and adds a subtle sweetness and creaminess to both savory and sweet dishes.
Roasted or mashed, butternut squash transforms familiar recipes. When puréed, it becomes velvety and light, which is exactly why this Butternut Squash Casserole works so well: the purée creates an airy, custard-like base that pairs perfectly with a hearty streusel.
This casserole is a lighter alternative to sweet potato casseroles—still warm and comforting, but milder in flavor and lower in carbs. It’s an unexpected twist guests will appreciate.
Why you’ll love this recipe:
- Light, fluffy texture from homemade butternut squash purée, balanced by maple syrup and warm spices.
- Pecan-oat streusel adds crunch and a nutty, toasty finish.
- Make-ahead friendly: purée can be made up to 3 days ahead and the casserole assembled the day before baking.
- Easy to adapt: swap vegan butter and gluten-free flour to make it dairy- and gluten-free.
Recipe ingredients
This casserole uses simple pantry ingredients and can be customized with what you have on hand.
- Butternut squash: Homemade purée has fresher flavor and thicker texture than canned. It can be made up to 3 days ahead.
- Maple syrup: Adds fall flavor; honey or another sweetener can be substituted.
- Butter and milk: Use vegan butter and non-dairy milk for a dairy-free version. Full-fat milk will make the casserole richer.
- Flour: Use a gluten-free 1:1 flour or a mix of oat and almond flour to make the streusel gluten-free.
- Rolled oats: Add chew and texture to the streusel.
- Brown sugar: Swap coconut sugar for a refined-sugar-free streusel.
- Pecans: Walnuts work as a substitute, or omit nuts for allergies.
See the ingredient list in the recipe card below for exact quantities.
How to make this recipe
The casserole has three components: prepare the butternut squash purée, make the filling, and prepare the streusel. Each is straightforward and can be prepped ahead; assemble the casserole and bake when ready.
Pro tip: The purée is the most time-consuming part, but it’s the key to flavor and texture. Homemade purée drains a bit of excess liquid for a thicker final filling—allow draining time in the fridge if possible.
- Cut the butternut squash in half, rub with oil and roast cut-side down until fork tender (about 35–45 minutes at 375°F). When cool, scoop out the flesh and purée until smooth.
- Optional but recommended: place the purée in a fine mesh sieve lined with cheesecloth over a bowl, cover loosely and refrigerate overnight to drain excess liquid.
- Beat the drained purée with eggs, maple syrup, milk, melted butter, cinnamon, vanilla and salt until smooth. Pour into a greased baking dish.
- Make the streusel by combining oats, flour, brown sugar, pecans, cinnamon, cardamom and a pinch of salt. Cut in cold butter until pea-sized clumps form. Sprinkle evenly over the filling.
- Bake at 350°F for about 45 minutes, until the streusel is golden and the center is set. Cool 10 minutes before serving.
Recipe FAQs
Butternut squash purée is mild and naturally sweet, somewhere between pumpkin and sweet potato. It adds richness without being overly heavy, making it versatile in both savory and sweet dishes.
Canned purée will work and saves time, but homemade purée tends to be fresher and thicker, which improves the texture of the casserole.
Store homemade butternut squash purée in the refrigerator for up to 3 days or freeze for up to 3 months.
Use vegan butter and non-dairy milk for the filling, and substitute the all-purpose flour with a gluten-free 1:1 flour or a blend of oat and almond flours in the streusel.
Serving suggestions
This casserole shines as a holiday side dish but is equally welcome at any fall or winter dinner.
- Serve at Thanksgiving with roast turkey or ham.
- A lovely accompaniment for Christmas dinner alongside roasted poultry or glazed ham.
- Bring it to potlucks or Friendsgiving gatherings—it’s easy to transport and reheat.
- For a cozy weeknight, serve with roasted pork chops or pan-seared steak, or make it the star of a vegetarian meal with a simple green salad.
Recipe notes
- Make ahead: Purée the squash up to 3 days in advance. The casserole can be fully assembled the day before and baked just before serving.
- Allergy swaps: Use vegan butter and gluten-free flour to accommodate dairy- or gluten-free diets. Replace pecans with walnuts or omit nuts if needed.
- Sugar swaps: Maple syrup can be replaced with honey or another preferred sweetener. Use coconut sugar in the streusel for a refined-sugar-free option.
- Storage: Refrigerate leftovers for 3–5 days and reheat gently until warmed through.
Butternut Squash Casserole with Streusel Topping — Recipe Card
Servings: 12 | Prep time: 30 mins | Cook time: 1 hr 20 mins | Drain time: 8 hrs (optional)
Butternut Squash Casserole is fluffy and delicious with homemade purée and a hearty pecan-oat streusel. It can be made ahead for easier holiday cooking.
Equipment
- Rimmed baking sheet
- Food processor or blender
- 8×8″ baking dish
- Fine mesh sieve and cheesecloth (optional, for draining purée)
Ingredients
For the casserole:
- 1 tablespoon oil
- 1 large butternut squash, halved and seeded
- 4 large eggs
- 1/3 cup pure maple syrup
- 1/2 cup milk (dairy or non-dairy)
- 4 tablespoons unsalted butter, softened
- 2 teaspoons ground cinnamon
- 2 teaspoons vanilla extract
- 1/2 teaspoon salt
For the streusel:
- 1/2 cup old fashioned rolled oats
- 1/2 cup all-purpose flour (or gluten-free substitute)
- 1/3 cup light brown sugar, packed
- 1/2 cup pecan pieces
- 1 teaspoon ground cinnamon
- 1/4 teaspoon sea salt
- 6 tablespoons unsalted butter, cold and cubed
Instructions
- Preheat oven to 375°F. Line a rimmed baking sheet with foil. Rub squash halves with oil and roast cut-side down 35–45 minutes, until fork tender. Cool, scoop flesh and purée until smooth (you should have about 4–4½ cups).
- Optional: transfer purée to a cheesecloth-lined sieve over a bowl, cover loosely and refrigerate overnight to drain excess liquid.
- Preheat oven to 350°F. Spray an 8×8″ baking dish with cooking spray.
- Beat together drained purée, eggs, maple syrup, milk, butter, cinnamon, vanilla and salt until smooth. Pour into prepared dish.
- Make streusel: combine oats, flour, brown sugar, pecans, cinnamon and salt. Cut in cold butter until pea-sized clumps form. Sprinkle evenly over filling.
- Bake at 350°F for about 45 minutes, until streusel is golden and the center is set. Cool 10 minutes before serving.
Notes
- This casserole is make-ahead friendly and adaptable for dietary needs.
- Leftovers keep 3–5 days in the refrigerator.
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