🍠🙌🧡 Classic Sweet Potato Marshmallow Casserole combines tender and creamy sweet potatoes, the subtle crunch of a buttery pecan crumble, and gooey marshmallows for a comfort food side dish that’s an automatic family FAVORITE! It’ll be on repeat for your Thanksgiving, Christmas, and holiday celebrations every year!
Classic Sweet Potato Casserole Recipe
Nothing screams “Thanksgiving” like sweet potato marshmallow casserole topped with pecans! When I think of classic Thanksgiving side dishes, I can’t think of anything more traditional.
For this recipe, I used my favorite Sweet Potato Casserole with Pecan Topping recipe as a jumping-off point. Being that it’s such a fan favorite due to those sweet, creamy, and tender sweet potatoes, topped with the most lovely buttery pecan crumble topping for a texture contrast that I personally adore, it was about time for a marshmallow-topped rendition.
Today’s recipe is virtually the same, but with a marshmallow twist. My daughter says they’re her favorite part!
Looking for more holiday side dishes?
Add my creamy make ahead mashed potatoes, chicken broth gravy, smothered bacon green bean casserole, and garlic herb rolls to your table, too!
Marshmallow Sweet Potato Casserole Ingredients
For this sweet potato casserole with marshmallows and pecans, you’ll need the following easy-to-find ingredients:
- Sweet potatoes – The best advice here is to weigh your potatoes on the grocery store scale in the produce department. That is the only way you’ll know for sure. Sometimes you’ll come across massive jumbo sweet potatoes that weigh close to two pounds each! Whereas other times you’ll find more petite or long cylindrical potatoes. Therefore, don’t guess and go by the actual weight
- Eggs
- Unsalted butter – Use a plant-based butter, if needed
- Milk – Whole milk will create the richest flavor, but any regular or dairy-free milk will work
- Sugar – A combination of light brown sugar and granulated sugar sweetens the casserole, keeping it moist and adding a subtle molasses taste
- Vanilla extract
- Spices – Salt, ground nutmeg, and cinnamon add delicious warmth and depth
- All-purpose flour – Use a 1:1 all-purpose gluten-free flour if you need to keep this casserole gluten-free
- Pecan halves
- Mini marshmallows – While the recipe states 2 1/2 cups marshmallows, if you want to bump that up to closer to 3 cups, or whatever you need to exactly cover your casserole dish, go for it. Don’t be skimpy with the marshmallows since they happen to be many people’s favorite part of this Thanksgiving side dish
Note: Scroll down to the recipe card section of the post for the ingredients with amounts included and for more complete directions.
How to Make Sweet Potato Casserole with Marshmallow Topping
As I mentioned, I used my favorite Sweet Potato Casserole recipe as the base, and then added marshmallows. If it ain’t broke, don’t fix it!
- Cook the sweet potatoes in a large stockpot of boiling water until they’re fork-tender.
- Add the drained sweet potatoes to a large bowl along with the eggs, butter, milk, brown sugar, granulated sugar, vanilla, salt, nutmeg, and cinnamon. Transfer the sweet potato mixture to a greased 9×13-inch casserole dish. Set aside.
- Prepare the topping by melting the butter, then using a fork, toss it with brown sugar, flour, and salt. Add the pecans last.
- Sprinkle the topping over the sweet potatoes in your baking dish.
- Bake the sweet potato casserole until the top is lightly golden brown, the edges are set, and the center is mostly set. In the final 5 minutes of baking, add the marshmallows and bake until they’re golden brown.
Tip to Prevent Overflow
I suggest placing your baking dish on top of a sheet pan when baking the marshmallow sweet potato casserole. If there’s any overflow — of either the crumble topping or later on with the marshmallows — the sheet pan underneath is great insurance to catch an accidental overflows so you don’t have to clean your oven after an already long day in the kitchen.
Make-Ahead Instructions
You can assemble the entire casserole the night before, cover it tightly with foil, and refrigerate it until ready to bake.
I suggest letting the casserole sit at room temp on your counter for 30 to 45 minutes before baking if you have refrigerated it overnight, so that you don’t need to extend the baking time at all.
Recipe FAQs
I recommend baking your Thanksgiving sweet potato casserole for roughly 40 to 45 minutes at 350ºF. Start checking the casserole at 30 minutes. Bake just until the top is lightly golden browned, set on the edges, and mostly set in the center.
When you’re mixing together the boiled sweet potatoes with the other ingredients including the sugars, eggs, and milk, I recommend beating the ingredients together with a handheld electric mixer for a nice, smooth texture. Although you can use a potato masher for this task if you like a chunkier texture.
No, you do not need to cover the casserole with foil when baking. The marshmallows are added near the end of the bake time, so there’s no risk of them burning in the oven!
If you let the sweet potato cubes cook in the boiling water for more than 20 minutes, they’ll absorb excess water and become soggy once mashed. If after boiling the sweet potatoes they seem at all watery to you, simply add less milk to the filling than the recipe calls for to balance things out.
Storage and Reheating
In the fridge: Store airtight for up to 1 week.
In the freezer: Store airtight for up to 4 months. However, I recommend freezing it without the marshmallows on top for best results.
To reheat: First, let it sit at room temp for at least 15 to 30 minutes if you can plan ahead. Then, you can reheat the casserole in either the microwave or the oven. Reheat in 30-second bursts in the microwave. Reheat in a 325ºF oven for 15 to 20 minutes.
What to Serve with Marshmallow Sweet Potato Casserole
Recipe Video Tutorial
Classic Marshmallow Sweet Potato Casserole
Ingredients
Sweet Potato Filling
- 4 pounds raw sweet potatoes, peeled, diced into large chunks, and boiled
- 2 large eggs
- ¼ cup unsalted butter, softened
- ½ cup milk*, (See Notes)
- ½ cup light brown sugar, packed
- 2 tablespoons granulated sugar
- 1 teaspoon vanilla extract
- ½ teaspoon salt, or to taste
- ¼ teaspoon ground nutmeg, optional
- ¼ teaspoon cinnamon, optional
Topping
- 5 tablespoons unsalted butter, melted
- ⅔ cup light brown sugar, packed
- ½ cup all-purpose flour
- ¼ teaspoon salt, or to taste
- 1 cup pecan halves
- 2 ½ to 3 cups mini marshmallows, or as needed
Instructions
Sweet Potato Filling:
- To a large stockpot, add the sweet potato chunks, cover with water, and bring to a boil. Cook over high heat until sweet potatoes are fork tender; about 20 minutes. Drain well and transfer to a large bowl.
- Preheat oven to 350F and spray a 3 to 4-quart baking or casserole dish or a 9×13-inch baking pan with cooking spray; set aside.
- To the large bowl with the sweet potatoes, add the eggs, butter, milk, brown sugar, granulated sugar, vanilla, salt, optional nutmeg, optional cinnamon, and beat with a handheld electric mixer on medium-high speed until combined and fluffy. Alternatively, if you prefer a coarser texture that’s more chunky, you can use a potato masher.
- Turn out into baking dish, smoothing the top lightly with a spatula; set aside.
Topping:
- To a large microwave-safe bowl, add the butter and heat on high power to melt, about 1 minute.
- Add the brown sugar, flour, salt, and gently toss with a fork (or your fingers) until moist crumbs form.** (See Notes for Tips)
- Add the pecans and gently toss to incorporate.
- Evenly turn topping out over filling.
- If making ahead of time – stop now. Cover tightly with foil, and refrigerate for up to 24 hours. If you’ve made it ahead, allow the sweet potato casserole to sit out at room temp for 30 to 60 minutes. Don’t put it straight into the oven from the fridge because the baking time will be altered.
- Bake the sweet potato casserole for about 40 to 45 minutes; start checking at 30 minutes. Bake until top is lightly golden browned, set on the edges, and mostly set in the center. Tip – Place baking dish on a sheet pan to catch any accidental overflow to save on cleanup later.
- Remove the casserole from the oven, evenly sprinkle with the marshmallows, and bake for 5 minutes more, or until the marshmallows are lightly golden browned. Tip -Keep a very watchful eye on the marshmallows since they are prone to burning. Set a timer so you don’t accidentally forget about it.
- Serve immediately. Extra will keep airtight for up to 1 week in the fridge and up to 4 months in the freezer.***(See Notes)
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
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More Sweet Potato Side Dishes:
All of my sweet potato recipes here!
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Sweet and Savory Sweet Potato Casserole — A fun and EASY twist on classic sweet potato casserole that uses potato chips in the topping for a SALTY-SWEET flavor the whole family will love! Great for Thanksgiving and Christmas celebrations!
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Honey Butter Smashed Sweet Potatoes — Soft, tender potatoes with crispy skin and the most HEAVENLY melted honey butter on top! EASY comfort food that’s a perfect side dish anytime!
Easy Homemade Candied Yams — Learn how to make the BEST candied yams which are baked in the most wonderful buttery cinnamon-and-sugar sauce! If you’re looking for an EASY Thanksgiving or Christmas side dish recipe, look no further than this EASY holiday recipe with almost no active prep time.
Best sweet potatoes I’ve made so far, family loved them last year and I’m making them again this year so good!
Thanks for the 5 star review, Trina, and I’m thrilled that these are the best sweet potatoes you’ve ever made and you’ve made them last year and going to make them again this year!
great
This looks amazing! I can’t wait to try it!! Can I omit the pecans?
Yes you can omit them. It will lack some of the crunch factor but will be fine.
great
You can keep more flavor of the potatoes if you bake them instead of boiling them.
I tend to agree for most sweet potato recipes but in sweet potato casseroles it’s more common to boil but of course not everyone does it this way.