This Sweet Potato Casserole is everything Southern comfort should be. This version skips the nuts but doubles down on the cozy factor with a buttery brown sugar streusel and toasted marshmallow topping. This casserole might just become your family’s new favorite tradition.
Sweet Potato Casserole has always been a holiday staple for us, but this recipe is the one I always come back to. It’s exactly how I love it—rich, creamy sweet potatoes with a topping that’s sweet, buttery, and toasted just right. After years of tweaking, I’ve perfected the balance. It’s comforting but never overly sweet, nostalgic without being complicated.
What sets this version apart is that it’s approachable enough for beginners but delicious enough to impress even your pickiest family members. Plus, there’s no fussing with extra steps or hard-to-find ingredients. It’s just a simple, cozy dish that makes holidays feel special and familiar, year after year.
Southern Sweet Potato Casserole Ingredients
- sweet potatoes
- cinnamon
- butter
- brown sugar
- flour
- marshmallows
How many sweet potatoes for sweet potato casserole?
To make sweet potato casserole, you will need 2 pounds of sweet potatoes. This is approximately 4-6 sweet potatoes depending on their size.
How to Make Sweet Potato Casserole with Marshmallows
(full recipe card below)
- Combine the ingredients for your streusel topping (butter, brown sugar, and flour). Set aside.
- Make your mashed sweet potatoes. You can do this in the Instant Pot (see recipe coming to the blog in just 2 days), or you can boil them on the stove.
- Once boiled and soft, drain them and add them back to the pot with butter and cinnamon. Mash until smooth.
- Spread your mashed sweet potatoes smoothly and evenly into a large casserole dish.
- Sprinkle half of the marshmallows across the top (there will be gaps at this point).
- Sprinkle half of the streusel topping across the top.
- Top with remaining marshmallows and streusel.
- Bake in the oven at 400°F for 6 minutes. WATCH CLOSELY. You do not want the marshmallows to burn.
- Remove from the oven and serve hot.
How to Cook Sweet Potatoes for Sweet Potato Casserole
Boiling sweet potatoes is quick, easy, and perfect for casserole because it gives you potatoes that are super creamy and easy to mash. Here’s exactly how to do it.
- Start by peeling your sweet potatoes, then cut them into evenly-sized chunks, about 1 to 2 inches each. Keeping them the same size helps them cook evenly.
- Place the cubed sweet potatoes in a large pot and fill it with enough cold water to fully cover them by about an inch. Sprinkle in a pinch of salt to enhance the flavor.
- Set the pot on the stove over high heat and bring the water to a boil.
- Once boiling, reduce the heat slightly to maintain a gentle boil, and cook for about 15-20 minutes, until the sweet potatoes are easily pierced with a fork.
- Drain the sweet potatoes well in a colander. Let them sit for a minute or two to release excess moisture. This keeps your casserole creamy, not watery.
- While they’re still warm, mash the sweet potatoes with a potato masher or electric mixer until smooth and creamy, then proceed with your casserole recipe.
Can you Make Sweet Potato Casserole ahead of time?
Yes, but you’ll need to wait to put the marshmallows and streusel on top. You can make the mashed sweet potatoes ahead of time and put them in the casserole dish. Cover with foil and place in the refrigerator until ready to bake. Then, once you’re ready to serve, top with the marshmallows and streusel and serve hot.
Sweet Potato Casserole Recipe Tips & Tricks
- Opt for the Instant Pot for making your mashed sweet potatoes. It makes this go by even faster!
- Alternating the marshmallows and streusel make sure that the streusel gets in all the nooks and crannies.
- Find the balance between too toasted (aka burned) and just the right amount of toasted on the marshmallows. I start keeping an eye on it closely around the 4 minute mark.
Sweet Potato Casserole with Marshmallows FAQs
Sweet potato casserole is done cooking when the potatoes are heated through and the marshmallows are slightly toasted. Be careful and watch closely. The marshmallows can go from toasted to burned very quickly.
If you are cooking your sweet potatoes in the oven, you’ll want to wait until the sweet potatoes are cooked through before adding the marshmallows.
If you are using sweet potatoes that are already cooked and just adding them either chopped or mashed to the casserole dish, you can add them immediately and place in the oven.
According to the USDA, cooked potatoes can be safely stored in the refrigerator up to 3 days when stored properly. If you plan to freeze sweet potato casserole, you can freeze for up to 6 months in advance.
It is important that your cooked sweet potatoes are fully drained before adding them to the casserole. Any additional water or condensation left in the potatoes will be released when you bake the casserole.
If you opted to boil your sweet potatoes, over boiling them can also cause them to absorb some of the water in the pot that may then get released into the casserole. The key to not having a runny sweet potato casserole is cooking your sweet potatoes properly.
If your sweet potato casserole seems too runny, you can easily fix it by adding a thickener. Stir in a tablespoon or two of flour or cornstarch to the sweet potato mixture before baking. Another great option is to cook the sweet potatoes a bit longer when boiling, allowing excess moisture to evaporate, and then make sure they’re well-drained before mashing. This helps keep your casserole creamy and perfectly thick every time.
How to store Sweet Potato Marshmallow Casserole
The recommended way to store sweet potato marshmallow casserole is in an airtight container in the refrigerator. It’s best when used within 3 days.
Be aware that the marshmallows will no longer be fluffy once stored in the refrigerator. They will lose their density, but the flavor will still be there.
How long can sweet potato casserole sit out?
Do not live sweet potato casserole sitting out at room temperature for more than 2 hours. According to the USDA, sweet potato casserole should be thrown out if left out at room temperature for more than two hours.
How long does sweet potato casserole last in the fridge?
Sweet potato casserole should be eaten within 3 days of being stored properly in the refrigerator for not only freshness but also for safety.
Can you freeze sweet potato casserole?
Yes, you can absolutely freeze sweet potato casserole. For this recipe, I would recommend omitting the topping and freezing prior to the topping. When you’re ready to bake, allow it to thaw in the refrigerator overnight. Add the topping right before baking.
How to reheat Sweet Potato Casserole
Leftover sweet potato casserole is best when reheated in the oven. You can reheat this quintessential Thanksgiving side dish in a 350°F oven for 15 minutes. If you prefer, you could also reheat in the microwave.
What to Serve with Southern Sweet Potato Casserole
Sweet Potato Marshmallow Casserole
Ingredients
- 2 lbs sweet potatoes
- 1 tsp + 1/2 tsp cinnamon
- 2 tbsp + 5 tbsp butter softened & divided
- 1 tbsp + 4 tbsp brown sugar
- pinch of salt
- 5 tbsp flour
- 2 cups marshmallows
Instructions
- Preheat oven to 400°F.
- Combine 1/2 tsp cinnamon, 5 tbsp butter, 4 tbsp brown sugar, and flour. Combine until it becomes a sticky, sand like consistency. Set aside.
- Make your mashed sweet potatoes. You can do this in the Instant Pot (see recipe coming to the blog in just 2 days), or you can peel and boil them on the stove.
- Once boiled and soft, drain them and add them back to the pot with 1 tbsp brown sugar and the remaining butter and cinnamon. Mash until smooth.
- Spread your mashed sweet potatoes smoothly and evenly into a large casserole dish.
- Sprinkle half of the marshmallows across the top (there will be gaps at this point).
- Sprinkle half of the streusel topping across the top.
- Top with remaining marshmallows and streusel.
- Bake in the oven at 400°F for 6 minutes. WATCH CLOSELY. You do not want the marshmallows to burn.
- Remove from the oven and serve hot.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
My sweet potato casserole recipe has pecans but now I have to make one without (because of allergies) and this is the ONLY one that is so good that I don’t miss the old recipe!