Vegan Squash Casserole
Add Preferred SourceEvery bite of this Vegan Squash Casserole gives you tender butternut squash and sweet caramelized leeks soaked in asparagus cream, all baked under a crispy golden breadcrumb crust. Fresh sage adds that earthy warmth you crave in fall, and the topping gives you crunch with every creamy, comforting forkful that’ll have everyone asking for more.
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I make this for Thanksgiving, Christmas, Friendsgiving, and fall potlucks because it feeds a crowd and travels well. It’s the perfect holiday side dish with that Southern comfort food feel everyone loves. The casserole reheats beautifully in the oven or microwave and stays fresh in the fridge for 4 days or freezes for up to 3 months.
Ingredients You’ll Need
You’ll need all the ingredients shown in the photograph below.
How to Make Vegan Squash Casserole with Step-By-Step Instructions
Scroll down for the full recipe card containing a full printable recipe and measurements in both US customary and metric units.
Here’s how to make this golden, layered casserole from start to finish.
Roast the Butternut Squash
Preheat your oven to 400°F and line a baking sheet with parchment paper. I like using this oven thermometer to check that my oven temperature is accurate,
Stir the cubed butternut squash with olive oil and a pinch of salt, then spread it in a single layer. Roast for 25 to 30 minutes until the edges are tender and golden. Use a silicone spatula to flip the squash halfway through so it roasts evenly on all sides.
Caramelize the Leeks with Sage
While the squash roasts, melt the vegan butter in a large sauté pan over medium heat. Add the sliced leeks, minced garlic, and chopped sage, and cook for 10 to 12 minutes, stirring occasionally, until the leeks are soft, golden, and slightly caramelized for an extra flavor.
Season with salt and pepper. A salt and pepper grinder set gives you fresh, aromatic seasoning that makes a noticeable difference in the flavor. The leeks should smell sweet and buttery when they’re ready.
Layer the Casserole
Reduce your oven temperature to 375°F. Lightly grease a 9×9-inch or 8×11-inch casserole dish with cooking spray or vegan butter. A 9×13-inch ceramic baking dish works perfectly for this casserole and evenly distributes heat, resulting in a creamy sauce and a bubbly top.
Start by layering half the caramelized leeks on the bottom, then add the remaining half of the roasted yellow squash on top. Repeat with the remaining veggies: leeks and squash, making two complete layers.
Add the Asparagus Cream and Breadcrumbs
Pour the vegan asparagus cream evenly over the layered vegetables, letting it blend into the spaces between the squash and leeks. Sprinkle the breadcrumbs over the top. Use a measuring cup to distribute the breadcrumbs evenly, so they bake into a crispy, golden crust.
Bake Until Golden and Bubbly
Bake the mixture uncovered for 27 to 30 minutes, until the asparagus cream is bubbling around the edges and the breadcrumbs are golden brown. You’ll know it’s ready when the top is crispy, and the filling is hot all the way through.
Garnish and Serve
Remove the casserole from the oven and let it rest for 5 minutes to allow the layers to set. Garnish the top of the casserole with fresh herbs, such as parsley, and serve warm. Enjoy!
An insulated casserole carrier keeps the dish hot for hours, making it perfect for transporting to potlucks, holiday dinners, or family gatherings.
Equipment
- 9×13-inch ceramic baking dish
Ingredients
- 3 cups butternut squash cut into small cubes
- 1 tablespoon olive oil
- Pinch of sea salt
- 2 tablespoons vegan butter
- 2 cups sliced leeks
- 3 large cloves garlic minced
- 2 tablespoons fresh sage chopped
- 1 cup vegan asparagus cream soup
- ¾ cup breadcrumbs
- Salt and pepper to taste
- Fresh parsley for garnish
Video
Instructions
- Preheat the oven to 400°F (200°C).
- Toss the cubed squash with olive oil and a pinch of salt. Spread on a baking sheet and roast for 25–30 minutes, until tender.3 cups butternut squash, Pinch of sea salt, 1 tablespoon olive oil
- In a sauté pan, melt the vegan butter over medium heat. Add the leeks, garlic, and sage, and cook for 10–12 minutes, until soft and golden. Season with salt and pepper.2 tablespoons vegan butter, 2 cups sliced leeks, 3 large cloves garlic, 2 tablespoons fresh sage, Salt and pepper
- Reduce the oven temperature to 375°F (190°C).
- Lightly grease a 9×9-inch or 8×11-inch baking dish. Layer half the leeks, then half the roasted squash. Repeat the layers. Pour the asparagus cream over the top and sprinkle with breadcrumbs.1 cup vegan asparagus cream, ¾ cup breadcrumbs
- Bake uncovered for 27–30 minutes, until bubbly and golden.
- Garnish with fresh parsley and serve warm.Fresh parsley
Notes
- Cut squash evenly: Cube the butternut squash into similar-sized pieces so they roast at the same rate and you don’t end up with some pieces too soft and others undercooked.
- Don’t rush the leeks: Cook them low and slow for the full 10 to 12 minutes, so they caramelize and develop sweetness rather than soften.
- Use fresh sage: It has a stronger, earthier flavor than dried sage, and it makes a noticeable difference in the overall taste of the casserole.
- Customize with extras: Add fresh thyme alongside the sage, dollop vegan sour cream on top when serving, thin the asparagus cream with vegetable broth if needed, thicken it with cornstarch whisked in before baking, or use a blender to make a homemade cream sauce with oat milk and all-purpose flour for a dairy-free option from scratch.
- Try these swaps: Use 2 cups of diced yellow onion instead of leeks, swap breadcrumbs with crushed buttery crackers or gluten-free crackers for a richer topping, or replace half the butternut squash with sliced zucchini and reduce roasting time to 15 to 20 minutes.
- Flash freeze first: Freeze the casserole on a baking sheet for 1 hour before transferring to a container so the layers stay intact and don’t stick together.
Nutrition
How to Store Leftovers
Let the casserole cool completely before storing. Transfer it to an airtight container and refrigerate for up to 4 days. Reheat individual portions in the microwave for 1 to 2 minutes, or warm the whole casserole in a 350°F oven for 15 to 20 minutes until heated through.
For longer storage, freeze the casserole in a freezer-safe container for up to 3 months. A freezer-safe glass container with a tight-sealing lid prevents freezer burn and keeps the casserole fresh.
Thaw it overnight in the fridge, then reheat in the oven until bubbly. The breadcrumbs might soften slightly after freezing, but they’ll still taste great.
What to Serve With Vegan Squash Casserole
This casserole pairs beautifully with roasted Brussels sprouts, garlic green beans, or a simple arugula salad with lemon vinaigrette. I also love serving it alongside wild rice pilaf or quinoa for a complete meal. The creamy, savory flavors work well with fresh, crisp vegetables or hearty grains.
For holiday dinners, it complements dishes like vegan mashed potatoes, cranberry sauce, and roasted root vegetables perfectly. The butternut squash and sage make it feel festive without being too heavy, so it fits right in with traditional Thanksgiving and Christmas spreads.
More Easy Casserole Recipes for You to Try at Home
I think you’ll also love these other plant-based casseroles perfect for holidays and gatherings.
