Cheesy Butternut Squash Casserole
Okay, I have to admit up front: Cheesy Butternut Squash Casserole is that dish I make when I want the whole house to smell like autumn Sundays. My uncle Jerry thinks I add something secret to make it disappear at potlucks, but I promise it’s just this recipe (well, maybe a bit more cheddar than strictly necessary). It all started a few years back when I tried to replicate this fancy dish from a restaurant down the street. News flash: theirs had way less cheese than mine—amateurs. Anyway, I’ve tweaked and fiddled so much that I sort of forget the original, but honestly, this version is so good, I don’t think I’ll ever go back. Plus, peeling squash is great for working out kitchen-related frustration (I always seem to pick the hardest squash, sigh).
What Makes This One a Keeper
I make this when I’m feeling, you know, kinda cozy and want comfort food but I also want to trick my family into eating veggies. My kids absolutely demolish it—and they’re suspicious of anything orange unless it’s a Cheeto (they’re children, what can you do?). Sometimes I serve it for Thanksgiving (saves the day if someone’s turkey is bone-dry, not naming names). Oh! And once or twice, I picked up pre-cut squash to save time—don’t let the supermarket guilt you—nobody’s judging.
Here’s What You Need (and What You Don’t)
- 1 large butternut squash (or about 4 cups if you go with pre-diced; honestly, frozen works fine, too; I won’t tell!)
- 2 tablespoons olive oil (sometimes I swap in melted butter, if I’m feeling fancy or out of oil)
- 1 medium yellow onion, chopped (red is fine, Grandma swore by Vidalia but it’s all good)
- 2-3 garlic cloves, minced (garlic powder in a pinch, just don’t tell anyone from Italy)
- 1 cup sour cream (Greek yogurt works, but gives it a twang—sometimes I mix both?)
- 2 cups shredded cheddar (I’ve used Monterey Jack, or a bit of mozzarella if the bag’s running low)
- 1/3 cup grated parmesan (I did it with the green can once, you know the one, and it was fine)
- 2 eggs
- 1/2 cup breadcrumbs (Panko brings the crunch, but crushed crackers if that’s all you’ve got!)
- 1/2 teaspoon salt, or just a couple pinches (I never measure, if I’m honest)
- 1/2 teaspoon black pepper
- Optional: a pinch of nutmeg or cayenne, if you want a wildcard in there
How I Throw It All Together
- First things first, heat your oven to 375°F (190°C). If you’re not sure if it’s hot enough—just stick your hand near it (not in!). Kidding. Kind of.
- Peel the butternut squash (if you still have fingerprints after, congrats) and dice it up. Toss with olive oil, salt, and pepper. Spread on a baking tray; roast about 25 minutes until soft, a little browned is good. I’ve used steamed squash before—it works, but roasting is way tastier.
- While that bakes, sauté the onion with a little olive oil in a big-ish skillet until it goes soft (sometimes I add a little garlic early, sometimes I forget and add it later; it’s survived every time).
- Mix up the eggs, sour cream, half the cheddar, all the parmesan, and a dash of nutmeg (if using) in a big bowl. Squirt a bit of lemon if you’re feeling wild. (This is where I taste test for salt—but you’ve got raw egg, so use your own judgement; I’ve lived this long, knock on wood.)
- Once your squash is cool enough that it doesn’t burn off your fingerprints, mash it a bit, then add it and the sautéed onion and garlic to the bowl. Stir it all together. It will look a little…oddly beige, but that’s normal.
- Pour into a greased casserole dish (I never measure the size, the one that fits works best!). Sprinkle breadcrumbs and the rest of the cheddar on top.
- Bake about 30 minutes, or until golden brown and bubbling at the edges. If you want extra crispy topping, you can broil it for a few minutes—but stay close, it can crisp up comically fast.
- Let it cool for 10 minutes if you value the roof of your mouth. Or just dive in; up to you.
Notes From a Serial Tweaker
- If you have leftover roasted squash, toss it in cold—the flavor’s actually better, I think, because it’s had time to settle.
- I used to put way too much parmesan thinking “it’ll get cheesier”—nope, it gets salty. Actually, going easy on the parm is wise.
- Once, I forgot to grease the casserole dish, and let’s just say…the cleanup was epic. Highly not recommended.
Variations That (Mostly) Work
- I once swapped half the squash for sweet potatoes—very good, but sweeter, so cut back a little on sugar (if you’re adding it at all).
- Chopped spinach stirred in before baking? Surprisingly nice, more colorful too.
- I tried a layer of sliced mushrooms on top; looked pretty, but got a bit watery. Not my favorite, but someone liked it!
My Go-To Gear (But Don’t Stress If You Don’t Have It)
- A sharp peeler makes all the difference; but if you only have a knife, just go slow. Or buy pre-cut! (Life’s too short for squash-related injuries.)
- Casserole dish: I use my old Pyrex, but any ovenproof dish—honestly, I’ve even done this in a deep pie plate, in a pinch.
- Big mixing bowl: If you only have small ones, mix in batches—I’ve done it. Gets a bit messy, but who’s judging?

How It Keeps (But Ours Never Makes It That Long)
Ideally, cover and refrigerate leftovers for up to 3 days. It reheats well in the microwave, though flavor is even better the next day. Or at least, that’s what I’ve heard—for real, it usually disappears overnight at my place. Freezes okay, but the texture loosens up a bit. Still tasty though.
Serving It Up, My Way
We usually just dig in straight from the dish (why dirty more plates). If I’m feeling energetic, I’ll add some fresh parsley or a dollop of extra sour cream on top. Sometimes we treat it as the main event with a leafy green salad; otherwise, it’s a rockstar side for roast chicken or, dare I say it, leftover pizza (trust me!).
A Few Lessons Learnt the Hard Way
- I once tried to speed up the roasting step—microwaving the squash. Texture got weird and watery; patience, in this one case, pays off.
- Don’t skip cooling before serving (if you like having tastebuds attached to your mouth).
- Tried doubling the breadcrumbs, thinking more crunch is better—it just turned into a bready hat. Less is more, apparently.
Questions People Have Actually Asked Me
- Can you prep this the night before?
- Sure thing. I assemble it all the way except for the breadcrumbs and cheese on top, then add those just before baking. Sometimes I get lazy and bake it straight from the fridge—the oven time just needs to be a bit longer.
- Is it vegetarian?
- Yep, as long as your cheese is vegetarian-friendly. Sometimes there’s sneaky animal stuff in parmesan, who knew?
- Can I make it gluten free?
- Oh yeah, just use gluten-free breadcrumbs (or rice crackers crushed up, or even skip the crumbs—I’ve done it accidentally and it still tasted good).
- Why is my casserole soggy?
- Usually it’s just excess water from the squash (especially if you used the microwave). Roasting helps a lot. And try not to add too much extra liquid—you want it thick-ish before baking.
- What cheeses work best?
- Cheddar’s my go-to, but Monterey Jack, Gruyere (if you’re feeling flush), or even a mix—the world’s your oyster. But actually, sharper cheeses pop the most.
- Do you ever top it with anything else?
- I tried adding fried onions once, like on green bean casserole (honestly, instant upgrade). Crushed potato chips? Oh, you bet. We ran out of breadcrumbs one year—sometimes mistakes are delicious.
By the way—if you’ve never, ever peeled a butternut and want some video backup, I can vouch for this Serious Eats guide. Or, I like poking around Smitten Kitchen for their home-cook takes; she’s got that same ‘figure it out as you go’ vibe. Maybe that’s why I keep coming back to this casserole—it’s forgiving in all the right ways, like a solid friend.
Ingredients
- 1 large butternut squash (about 2 lbs), peeled and cubed
- 1 cup shredded cheddar cheese
- 1/2 cup grated Parmesan cheese
- 1/2 cup milk
- 2 tablespoons unsalted butter
- 1/2 cup breadcrumbs
- 1/2 teaspoon garlic powder
- Salt and black pepper to taste
Instructions
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1Preheat oven to 375°F (190°C). Lightly grease a 2-quart baking dish.
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2Place cubed butternut squash in a large saucepan, cover with water, and bring to a boil. Cook for 10-12 minutes until tender. Drain well.
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3In a large bowl, mash the cooked squash. Stir in cheddar cheese, Parmesan cheese, milk, butter, garlic powder, salt, and pepper.
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4Transfer the mixture to the prepared baking dish and spread evenly. Sprinkle breadcrumbs evenly over the top.
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5Bake uncovered for 25-30 minutes, or until the top is golden brown and the casserole is bubbling. Serve warm.
Approximate Information for One Serving
Nutrition Disclaimers
Number of total servings shown is approximate. Actual number of servings will depend on your preferred portion sizes.
Nutritional values shown are general guidelines and reflect information for 1 serving using the ingredients listed, not including any optional ingredients. Actual macros may vary slightly depending on specific brands and types of ingredients used.
To determine the weight of one serving, prepare the recipe as instructed. Weigh the finished recipe, then divide the weight of the finished recipe (not including the weight of the container the food is in) by the desired number of servings. Result will be the weight of one serving.
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