This Sweet Potato Casserole with Marshmallows is just what you need for the ultimate holiday or weeknight side dish. Velvety-smooth sweet potatoes are topped with crumbly streusel and ooey-gooey roasted marshmallows. Serve this casserole with other holiday classics like Turkey, Brown Gravy, Dressing, and Turnip Greens.
If you appreciate sweets as much as I do, you will love digging into this decadent sweet potato casserole. A side dish like this always has everyone asking for the recipe!
No holidays in sight? No problem. You can find a spot for this sweet potato casserole on the dinner table any night of the year. It provides the perfect burst of sweetness to dishes that are savory-forward. You can also serve it as a hearty and satisfying dessert for Sunday family dinner!
What is Sweet Potato Casserole?
A Sweet Potato Casserole recipe is one of those dishes that truly encompasses Southern cuisine. During the holidays, you would be hard pressed to find a home without at least one on the table.
Formed in layers, the bottom features creamy sweet potatoes that are basically mashed infused with soul-warming spices like cinnamon and nutmeg. Next, an oat-based streusel adds a crispy, crumbly texture to every bite.
If you stopped there, it would already be a mouthwatering dish. But, the most exciting part comes from the sweet, pillowy-soft, and toasty marshmallow topping.
Whether you have tried Southern foods before or not, you will be hooked on this casserole after just one bite!
- Sweet potatoes — I prefer to boil my sweet potatoes as it’s the quickest, but you can also bake them. Sweet potatoes contain more Beta-carotene, a beneficial antioxidant, than any other fruit or vegetable by weight.
- Salted Butter — This casserole is quite sweet, so it’s important to incorporate savory elements that create balance. Salted butter adds liveliness to the casserole and aids in enhancing flavor.
- Brown Sugar — Brown sugar has a rich, caramel-like flavor due to the addition of molasses. Rather than produce an excessively sweet recipe, brown sugar creates depth. I love how it interacts with the spices, yielding an almost toffee-like taste.
- Whipping cream — To create the perfect sweet potato texture, whipping cream is a must! It provides rich, creamy, and satisfying flavors you wouldn’t be able to achieve with potatoes alone.
- Vanilla — To bring out the sweet, dessert-like nature of this dish. I always suggest using pure vanilla extract whenever possible!
- Cinnamon & Nutmeg — These two spices are a sweet potato’s best friend. Both aromatic and woody, their addition creates warmth and balances out the sweetness.
- Streusel — Combining typical streusel ingredients (flour, sugar, butter) with old-fashioned oats creates the perfect topping. Once baked, the oats make for a stunning textural element to offset the soft, creamy consistency of sweet potatoes.
- Marshmallows — Marshmallows are sticky, sweet, and tastiest when slightly toasted. If you love a good S’more, I promise you’ll love this sweet potato casserole with marshmallows.
How to Make Sweet Potato Casserole with Marshmallows
BOIL THE POTATOES – Boil the potatoes in a large stockpot until fork-tender. Completely drain the potatoes and transfer them back into the pot.
MIX THE POTATOES – Using a hand mixer (or a hand masher), blend the sweet potatoes until mostly smooth. Add butter, sugar, cream, vanilla, cinnamon, and nutmeg, then mix until well combined and smooth.
START ASSEMBLING – Preheat your oven to 350F, and grease a 9×13″ casserole dish. Spoon the mashed potatoes into the dish and smooth the top with a spatula.
MAKE THE CRUMBLE – Whisk together the flour, sugar, oats, cinnamon, and nutmeg in a medium bowl. Pour melted butter into the bowl of dry ingredients and mix with a fork to create crumbs.
LAYER IT – Layer marshmallows on top of the mashed sweet potatoes, then sprinkle the very top with the oat crumble.
BAKE – Bake the casserole until the crumble is crisp and the marshmallows are golden brown. For a torched marshmallow look, broil it for a few minutes at the end of baking.
With so many different ways to assemble a sweet potato casserole with marshmallows, make this recipe your own by tweaking a few of the layers.
For a crunchier option, swap out the streusel topping for chopped candied pecans. If you’re not a marshmallow fan, leave them off! Or, try a streusel-free casserole with only roasted marshmallows on top.
You can mix and match the top layers, add the streusel first, or the marshmallows. In the end, all versions will be equally delicious!
Broiling the marshmallows at the end of baking will give them a quintessential torched appearance that everyone knows and loves. You can also use a kitchen torch for more control.
Be patient with the sweet potatoes. No one likes a crunchy potato texture, so make sure they are very fork-tender before moving forward with the rest of this recipe.
The best part about making recipes in one big dish is how easy they are to store! Pop an airtight lid on your cooked sweet potato casserole, and it can be stored in the fridge for 4-5 days.
It is possible to freeze a baked sweet potato casserole. Make sure it’s completely cool, then cover it with an airtight lid or cling wrap and foil. I recommend storing it in an oven-safe container to make reheating easier.
If refrigerated, leave it at room temperature for at least 30 minutes before baking it. If frozen, I recommend thawing it overnight in the fridge and letting it reach room temperature before cooking.
Preheat your oven to 300 degrees F, cover the casserole with aluminum foil, and bake for 15 minutes. The foil will help the top layer from burning.
Sweet Potato Casserole with Marshmallows
For the Sweet Potatoes
- 3 1/2- 4 lbs sweet potatoes
- 1/3 cup salted butter
- 2/3 cup light brown sugar packed
- 3/4 cup heavy whipping cream
- 4 tsp vanilla extract
- 1 tsp ground cinnamon
- 1/4 tsp ground nutmeg
For the Crumble Topping
- 1/2 cup all purpose flour
- 6 tbsp light brown sugar packed
- 1/4 cup old fashioned oats
- 1/8 tsp ground cinnamon can go up to 1/4 tsp
- dash of nutmeg
- 4 tbsp salted butter
- marshmallows for topping
For the Potatoes
- Fill a large pot with sweet potatoes and water about an inch higher than potatoes. Bring to a boil over high heat. Cook until fork tender, about 15-20 minutes. Completely drain potatoes and place back into the pot.
- Using a hand mixer (or ah and masher), blend potatoes until mostly smooth. Next add butter, sugar, cream, vanilla, cinnamon and nutmeg and mix until well combined and potatoes are smooth.
- Preheat oven to 350 F. Grease a 9×13" casserole dish.
- Spoon mashed potatoes into dish and smooth with a spatula.
For the Crumble Topping
- Whisk together flour, sugar, oats, cinnamon and nutmeg in a medium bowl. Melt butter in a microwave safe bowl. Add melted butter to dry ingredients and mix with a fork to create crumbs.
- Add marshmallows to top of mashed sweet potatoes then sprinkle with crumble topping.
- Bake for 20-25 minutes or until crumble is crisp and marshmallows are golden brown. You can also broil marshmallows a bit if you want them to have a more torched look.
The best part about making recipes in one big dish is how easy they are to store! Pop an airtight lid on your cooked sweet potato casserole, and it can be stored in the fridge for 4-5 days. It is possible to freeze a baked sweet potato casserole. Make sure it’s completely cool, then cover it with an airtight lid or cling wrap and foil. I recommend storing it in an oven-safe container to make reheating easier. Reheating
If refrigerated, leave it at room temperature for at least 30 minutes before baking it. If frozen, I recommend thawing it overnight in the fridge and letting it reach room temperature before cooking. Preheat your oven to 300 degrees F, cover the casserole with aluminum foil, and bake for 15 minutes. The foil will help the top layer from burning.