Name: Easy Old-Fashioned Sweet Potato Casserole with Marshmallows
Prep time: 20 min
Cook time: 1 h 40 min
Total time: 2 h
Yield: 12
Cuisine: American
Ingredients: 4 lbs fresh sweet potatoes (Jewel or Garnet varieties are best); 1/2 cup (1 stick) unsalted butter, melted; 1/2 cup packed dark or light brown sugar; 1/4 cup milk or heavy cream; 2 large eggs; 1 tsp vanilla extract; 1 tsp ground cinnamon; 1/2 tsp ground nutmeg; 1/2 tsp salt; 1 (10-ounce) bag miniature marshmallows

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Every family has that one special dish that signals the holidays have truly arrived. In our house, it’s this very recipe for Sweet Potato Casserole with Marshmallows. The minute my son sees that puffy, golden-brown topping, I know the feast can officially begin!

I always get a little chuckle when I bring it to the table, because it starts the same, playful debate we’ve had for over twenty years.

My side of the family believes, with all our hearts, that a true Sweet Potato Casserole with Marshmallows must have that gooey, toasted topping. My dear husband, on the other hand, grew up with a crunchy pecan streusel.

For years, I actually made two separate dishes! But one busy, chaotic holiday, I decided to create this one perfect recipe.

This Sweet Potato Casserole with Marshmallows has the creamiest, most flavorful, old-fashioned sweet potato base rich with cinnamon and vanilla that even my husband had to admit was the best he’d ever tasted. And, of course, it’s finished with that beautiful blanket of marshmallows that still makes my son’s eyes light up.

This is the recipe that brought our family’s “great sweet potato debate” to a happy, delicious end. It’s simple, it’s reliable, and it’s just pure comfort. I’m so happy to be sharing it with you. 💛

Why You’ll Love This Recipe

Genuinely Creamy (Not Watery!) My secret is roasting the sweet potatoes instead of boiling them! Roasting concentrates all that wonderful, sweet flavor and makes the texture perfectly smooth and rich, never ever watery!

Perfectly Spiced: It’s full of all those cozy holiday spices, cinnamon, nutmeg, and a good splash of vanilla that just feel like a warm hug in every single bite.

The Ultimate Holiday Side: This is the classic, reliable, old-fashioned sweet potato casserole that you remember. It’s the perfect, comforting side dish that just belongs on your holiday table.

Make-Ahead Friendly! I know how busy holiday cooking can be! This is my favorite part. I’ll show you exactly how to prepare this casserole a day or two in advance, so all you have to do is pop it in the oven. It’s such a lifesaver!

Ingredients for a Classic Casserole

This recipe uses simple, wholesome ingredients that really let those beautiful sweet potatoes shine. There’s nothing fussy in here, just pure, old-fashioned goodness!

Ingredients for a classic sweet potato casserole with marshmallows, including fresh sweet potatoes, brown sugar, and spices.

For the Sweet Potato Base:

Fresh Sweet Potatoes: You’ll need about 4 pounds of fresh sweet potatoes. I find that varieties like Jewel or Garnet (the ones with the pretty reddish-purple skins) are the sweetest and have the creamiest texture for this casserole.
Unsalted Butter: One-half cup (1 stick), melted.
Brown Sugar: One-half cup, packed. You can use light or dark brown sugar, but I just love the rich, molasses flavor of dark brown sugar here.
Milk or Heavy Cream: One-quarter cup. Whole milk is perfectly fine, but if you want an extra-rich, decadent casserole, heavy cream is the secret.
Large Eggs: 2, to help the casserole set so it’s light and fluffy, almost like a soufflé.
Vanilla Extract: 1 teaspoon. Don’t skip this! It really rounds out all the warm flavors.
Spices: 1 teaspoon of ground cinnamon and 1/2 teaspoon of ground nutmeg. This is the classic holiday combination.
Salt: 1/2 teaspoon, just to balance all the sweetness.

For the Topping:

Miniature Marshmallows: One 10-ounce bag. We don’t skimp on the topping in this house!

Step-by-Step Instructions

Roast the Potatoes: First, preheat your oven to 400°F (200°C). Wash your sweet potatoes and pat them dry. Prick them a few times with a fork (this lets the steam escape) and place them on a baking sheet lined with foil for easy cleanup. Roast for 45-60 minutes, or until they are very tender and you can easily pierce them with a knife.

Ellie’s Note: I truly recommend roasting instead of boiling. Boiling can add extra water to your potatoes, leading to a runny casserole. Roasting makes the sweet potatoes sweeter and the flavor much richer!

Mash the Base: Let the potatoes cool just enough so you can handle them. Then, slice them open and scoop all that wonderful, soft flesh into a large mixing bowl. The skins should peel right off. Discard the skins. Reduce the oven temperature to 350°F (175°C).

Mix the Filling: Add the melted butter, packed brown sugar, milk (or heavy cream), the two eggs, vanilla extract, cinnamon, nutmeg, and salt to the bowl with the sweet potatoes.

Whip for Texture (My Tip!): Use a hand mixer to beat the filling on low speed for 1-2 minutes, until it’s perfectly smooth and a little fluffy. This is my secret to getting that creamy, almost soufflé-like texture. If you don’t have a hand mixer, a good potato masher will also work just fine.

Spread in Dish: Spoon the sweet potato filling into a 9×13-inch baking dish (or a similar 3-quart casserole dish) and spread it into an even layer. served warm.

Spreading the creamy Sweet Potato Casserole with Marshmallows filling into a baking dish before baking.

Bake the Base: Place the dish in the preheated 350°F oven and bake for 30-35 minutes. The casserole is done when the edges are bubbling slightly and the center is set (it shouldn’t be wobbly).

Add the Topping: Now for the grand finale! Remove the casserole from the oven. Sprinkle the miniature marshmallows evenly all over the top.

Sweet Potato Casserole with Marshmallows topped with mini-marshmallows, ready to be toasted in the oven.

Toast the Marshmallows: Return the dish to the oven for 5-10 minutes. Please watch it carefully! Marshmallows can go from perfectly golden to burnt in the blink of an eye. You just want them to be puffed, melted, and a beautiful light-golden brown.

Serve Warm: Let the casserole rest for about 10 minutes before serving. It’s best

Ellie’s Top Tips for Success

Here are my three little secrets for the perfect Sweet Potato Casserole with Marshmallows!

1. How to Settle the “Pecan Debate”

If your family loves both (like mine!), here’s my trick: Mix a simple streusel (1/2 cup pecans, 2 tbsp butter, 2 tbsp brown sugar) and sprinkle it over half the casserole before baking. Then, add your marshmallows to the other half at the very end. Everyone is happy!

2. Please, Don’t Burn the Marshmallows!

This is my most important tip for this Sweet Potato Casserole with Marshmallows! When you add that lovely marshmallow topping for the final 5-10 minutes, do not walk away. They go from perfect to burnt in a heartbeat! If you use the broiler, watch it every single second.

3. The Secret to “Creamy” (Not “Stringy”)

Sometimes fresh sweet potatoes can have little stringy fibers. My best secret for a wonderfully smooth casserole is to use a hand mixer to whip the filling! It breaks down any fibers and makes your Sweet Potato Casserole with Marshmallows wonderfully light, fluffy, and never stringy.

Common Questions (FAQ)

Can I use canned sweet potatoes (yams)?

I truly find that using fresh, roasted sweet potatoes gives you that real, old-fashioned sweet potato casserole flavor and a much creamier texture.

But, I know how busy the holidays get! If you’re in a pinch, you can use canned yams (you’ll need about 3 large 29-ounce cans). The most important step is to drain them very, very well and pat them dry before mashing. This keeps your casserole from getting watery!

How do I make this casserole ahead of time?

Oh, this is my favorite time-saver!

Just prepare the entire sweet potato filling (all the way up to spreading it in the dish).
Let it cool completely, then cover it tightly with plastic wrap and store it right in your baking dish in the refrigerator for up to 2 days!
When you’re ready to bake, let it sit on the counter for about 30 minutes to take the chill off, then bake as directed.
My most important tip: Do not add the marshmallows until the very end, just before serving!

Can I make this dairy-free?

Absolutely! It’s an easy swap.

Just use your favorite dairy-free butter substitute (the kind that comes in sticks works perfectly).
For the milk, you can use full-fat canned coconut milk (it’s wonderfully rich!) or any unsweetened almond or oat milk.

How do I know when the casserole is cooked through?

Before you add your marshmallows, your casserole should be “set.” This just means that if you gently wiggle the dish, the center shouldn’t be liquidy or jiggle like Jell-O. It should look firm, and the edges will often be just a little bit puffed and bubbly!

What to Serve With This Holiday Side Dish

This Sweet Potato Casserole with Marshmallows is truly the star of the side-dish table, isn’t it? It’s that warm, sweet, and comforting bite that’s right at home next to all the holiday classics.

We, of course, always serve this right alongside our Easy Oven Roasted Turkey Breast. It’s the perfect sweet and savory partner to that rich, juicy meat!

And don’t forget the other veggies! It’s just not a feast for me without a bright, crunchy, and savory Homemade Green Bean Casserole sitting right next to this creamy sweet potato dish. Oh, they’re just the perfect pair!

Storing & Reheating Leftovers

My goodness, if you’re lucky enough to have any of this wonderful Sweet Potato Casserole with Marshmallows left over, it makes the most delicious lunch the next day!

Just let the casserole cool down completely, then cover your baking dish tightly with foil or pop the leftovers into an airtight container. It will keep beautifully in the refrigerator for 3 to 4 days. Now, I will tell you, those lovely, puffy marshmallows will get a little soft and sticky in the fridge, but don’t you worry, that’s perfectly normal!

When you’re ready to reheat it, I find the oven is always best! Just place your leftovers in an oven-safe dish, cover it with foil (this keeps it from drying out!), and pop it into a 350°F oven for 15-20 minutes, until it’s warm all the way through.

And here’s my favorite “refresher” trick: for that last 5 minutes, I like to take the foil off and sprinkle on a few new mini-marshmallows! Oh, it’s just so good.

This Recipe is a Holiday Hug

From my kitchen to yours, I hope this old-fashioned sweet potato casserole with marshmallows brings as much warmth and happiness to your table as it does to ours. There is just something so special about sharing a dish that you know will make everyone smile, and this one is a guaranteed, crowd-pleasing, holiday hug.

It’s the perfect, sweet, and comforting partner to all those other holiday classics, like my Easy Oven Roasted Turkey Breast and a big, savory scoop of Foolproof Homemade Stuffing!

I do hope you’ll give this Sweet Potato Casserole with Marshmallows a try! If you do, please come back and leave me a comment and a rating below. I just love hearing how it turned out for you (and whether your family is Team Marshmallow or Team Pecan!).

And if you loved this recipe and want to save it for your holiday planning, please pin it to your favorite board on Pinterest! It’s the best way to keep it handy for when you need it.

Happy cooking!