This is the BEST Southern Sweet Potato Casserole Recipe!! Made with tender, creamy sweet potatoes, a buttery streusel topping, and toasted sticky-sweet marshmallows! This classic side dish stands out at any holiday or weeknight dinner table!
As you may have noticed, I’m a big fan of all things sweet. Even when it comes to everyday meals, I always seem to need to incorporate a touch of sugar. I love to douse filets of salmon in maple syrup and toss brown sugar into vats of beef stew. To me, the balance between sweet and savory is essential!!
Southern Sweet Potato Casserole is an almost dessert-like dish that feeds into my sugar addiction in the best way possible. You may think this simple and traditional casserole is only meant to be served at a holiday table but, you deserve a weeknight indulgence.
This old-fashioned sweet potato casserole is perfect to serve up with all kinds of main courses! I especially love it with Honey Glazed Ham, Fried Turkey, or even for a simple dinner or Oven Fried Chicken Tenders.
Take a risk tonight, treat yourself and let’s get our casserole on, shall we?
What is Sweet Potato Casserole?
Southern sweet potato casserole is one of the quintessential Southern side dishes. At almost any Southern holiday dinner table you can find a pyrex dish full of hot, potatoey goodness.
- Layer #1: Making this sweet potato recipe starts with a layer of smooth mashed sweet potatoes that have been loaded with warming spices.
- Layer #2: It’s followed by a mixture of brown sugar, oats, butter, and more spices to create the most satisfyingly crisp crumble.
- Layer #3: Marshmallows act as the final touch to make each bite smoky, sweet, and beyond indulgent.
If your mouth isn’t watering yet, I promise it will be once you take that first glorious bite. This casserole is a must-have in your Southern recipe tool belt!
In order to make the best sweet potato casserole with marshmallows you will need a handful of ingredients hopefully, many you already have on hand! Let’s look at the most important.
- Sweet potatoes: This simple sweet potato casserole uses fresh sweet potatoes.
- Cinnamon and nutmeg: These two spices are sweet potatoes’ best friend; both are aromatic and woody. Their addition helps to create warmth while also balancing out the sweetness.
- Light brown sugar: Contributes a deep, caramel-like flavor due to the added molasses, adding depth rather than an excessive amount of sweetness. I absolutely love how the sugar interacts with the spices to create warmth and an almost toffee-like taste.
- Old-fashioned oatmeal: The oats are tossed with flour, sugar, and butter. When baked the oats create the perfect crunch. My preference is for old-fashioned oats rather than quick oats which are more processed and in smaller pieces.
- Dairy: Butter and heavy whipping cream add richness to the first layer and also help make the mashed sweet potatoes ultra-creamy.
- Marshmallows: Marshmallows are sticky, sweet, and tastiest when slightly toasted. I love to use the jumbo marshmallows but you can also use the little ones.
How to Make This Recipe
Casseroles are notoriously easy to make; they consist of various layered components to make for one easy, delicious dish.
Whether made as a side dish or as the main event, casseroles are always a big hit in my home. Let’s look at how easy it is to assemble this recipe.
- First, fill a large pot with sweet potatoes and water about an inch higher than the potatoes. Bring the water to a boil over high heat and cook until the potatoes are fork tender, about 15-20 minutes. When ready, drain potatoes well and place them back into the pot.
- Use a hand mixer (or ah and masher) to blend potatoes until mostly smooth.
- Once smooth, add the butter, sugar, cream, vanilla, cinnamon, and nutmeg and mix until well combined and the potatoes are smooth.
- Spoon the mashed potatoes into the dish and smooth with a spatula.
- Combine the flour, sugar, oats, cinnamon, and nutmeg in a medium bowl and blend together with a whisk. Add melted butter to dry ingredients and mix with a fork creating a crumbly mixture.
- Add marshmallows to the top of mashed sweet potatoes.
- Last, sprinkle the crumble topping over the top of the sweet potatoes.
- Bake for 20-25 minutes or until crumble is crisp and marshmallows are golden brown.
What Goes With Sweet Potato Casserole?
Southern sweet potatoes are a standard for most holidays! In my family, it’s always served up with a variety of other sides.
- Creamy Mashed Potatoes
- Green Bean Casserole
- Broccoli Cheese Casserole
- Creamed Spinach
- Baked Macaroni and Cheese
For the main course, turkey or ham are always popular at holidays but this easy sweet potato casserole can be served up year around!
How to Store
This dish is perfect for leftovers and to make ahead! Store leftovers in the refrigerator for up to five days.
Looking to save a little time? Then plan to make ahead sweet potato casserole!! Whip up your sweet potato mixture up to three days in advance and store it in your refrigerator. Be sure to leave the marshmallows off until you’re ready to bake. Let the casserole dish sit out at room temperature for at least 30 minutes before topping and baking.
How to Reheat
Similar to green gean casserole and broccoli cheese casserole, in order to reheat sweet potato casserole, transfer the leftover casserole to a baking dish with the toppings on the top layers as much as possible. You can add more marshmallows and oat crumble mixture to the top if you want it to cook up crispier again the second time around. Heat in a 350° F oven until heated through, about 15-20 minutes.
You can also reheat it in the microwave but the topping will lose a bit of its crispness.
Can You Freeze Sweet Potato Casserole?
Yep! It freezes great! You can freeze it right in the baking dish or carefully transfer it to a storage container with the toppings on top. Store it in the freezer for up to three months.
- Layer it the way you like! The ratio of sweet potato, crumble and marshmallow is yours to play with when making marshmallow sweet potato casserole. No matter how it comes together, it’s bound to be tasty!
- Broil the top. For a more torched look on the marshmallows, place the casserole under the broiler after cooking it in the oven.
- Make ahead. Add the marshmallows and crumble topping right before baking!
If the potatoes are cooked on the same day the casserole is assembled and served, it will last up to five days. If the sweet potatoes are cooked in advance by a few days, deduct the number of days already refrigerated from five to calculate how long it will last. Be sure to store the leftovers in an airtight container.
I can’t be the only one who has looked at a strangely delicious dish and thought “who in the world invented this?”. Every recipe has started somewhere and, more often than not, the history behind it is fascinating. Candied sweet potatoes have been enjoyed in the Americas for over two hundred years! But, the first recipe for this casserole that included marshmallows was published in 1917. The recipe was used by a marshmallow manufacturer as a marketing ploy to sell more of their product.
More Sweet Potato Recipes
I don’t know who needs to hear this, but you need more sweet potatoes in your life. They’re sweet, starchy and so incredibly versatile.
Here are a few of Grandbaby Cakes’ BEST sweet potato recipes:
- Sweet Potato Pound Cake
- Southern Spiced Sweet Potato Biscuits
- Southern Sweet Potato Pie
- Sweet Potato Grits
- Sweet Potato Cinnamon Rolls
- Mashed Sweet Potatoes
- Roasted Sweet Potatoes recipe
- Baked Candied Yams
- Garlic Butter Sweet Potato Fries
- Candied Sweet Potatoes Recipe
*Did you make this recipe? Please give it a star rating and leave comments below!* Post a photo of how your version of the recipe came out on Instagram (using #grandbabycakes)!!
Sweet Potato Casserole
For Sweet Potatoes
- 3 1/2 lbs sweet potatoes
- 1/3 cup salted butter
- 2/3 cup light brown sugar packed
- 3/4 cup heavy whipping cream
- 1 tbsp 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
- 1/2 tsp ground cinnamon
- 1/8 tsp ground nutmeg
- 4 tbsp salted butter melted
- Marshmallows for topping 6 rows of 4 cover the whole pan
For the Potatoes
- Fill a large 8 qt pot with sweet potatoes and water about an inch higher than potatoes. Bring to a boil over high heat. While the potatoes are boiling, reheat the oven to 350 F. Grease a 9×13" casserole dish. Cook until fork tender, about 20-30 minutes, depending on the size of the potatoes. Completely drain potatoes and place back into the pot.
- Peel the skin off the potatoes and add to a large mixing bowl. Using a hand mixer (or a masher), blend potatoes until mostly smooth. Next add butter, sugar, cream, vanilla, cinnamon and nutmeg and mix until well combined and potatoes are smooth.
- 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 until well combined to create crumbs. Sprinkle the potatoes with the topping.
- Add marshmallows to top of crumble topped potatoes. Create 6 rows of 4 regular sized marshmallows to cover the whole pan.
- 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.
This post was originally published in March 2020, it has been updated for content in new images in August 2002.