This post may contain references to products from one or more of our advertisers. Oh Sweet Basil may receive compensation when you click on links to such products.
This Sweet Potato Casserole with Marshmallows and Brown Sugar Streusel is the ultimate holiday side dish! Inspired by the famous Ruth’s Chris version, this recipe takes it up a notch with gooey marshmallows, a buttery streusel crumble topping, and the perfect balance of sweetness. It’s easy to make, always a crowd favorite, and kids love it.
We made it again for Thanksgiving, and it was hands down the best side dish on the table. It’s so good I’m already planning to bake it for Christmas, and honestly, it’s perfect for Easter dinner too.
Sweet Potato Souffle with Marshmallows
Several years ago, my four-year-old helped me make this sweet potato casserole, and she was so proud she called Cade to announce she had just made “the best dinner ever.” It was not dinner on its own, but she really did help, and she loved it. A toddler loving sweet potatoes? That is the magic of this recipe.
I used to hate “yams” at Thanksgiving. They were syrupy, mushy casseroles with burnt marshmallows that no one really wanted to eat. Once I learned how to cook sweet potatoes the right way, everything changed.
This version is more of a sweet potato soufflé. It is light, fluffy, perfectly sweetened, and topped with gooey marshmallows and a brown sugar streusel. It is the best of both worlds, and your guests will be begging for the recipe.
Sweet Potato Casserole Ingredients
This is the perfect addition to any dinner menu. To make this easy sweet potato casserole recipe with marshmallows, you’ll need:
- Sweet Potatoes: the base of the casserole, naturally sweet and creamy
- Unsalted Butter: adds richness and smooth texture
- Salt: enhances flavor and balances sweetness
- White Sugar: sweetens the mashed sweet potatoes
- Brown Sugar: adds depth and caramel-like sweetness to the topping
- Cinnamon: a warm spice that complements the sweet potatoes. Pumpkin Pie Spice would also work in a pinch!
- Vanilla Extract: enhances flavor with a subtle sweetness
- Whole Milk: creates a creamy, smooth consistency
- Mini Marshmallows: classic topping that melts into a gooey layer
- All-Purpose Flour: binds the streusel topping together
- Panko Bread Crumbs: adds a light, crispy texture to the topping
- Graham Cracker Crumbs: adds a sweet, nutty crunch
How to Make Sweet Potato Casserole
This sweet potato recipe might not be as easy as dumping canned yams into a casserole dish and topping them with marshmallows, but it’s pretty easy nonetheless! Here’s how to make this sweet potato dish:
- Bake: Cook the fresh sweet potatoes until they are fork-tender.
- Peel: Remove the sweet potato skins and mash the sweet potatoes with a potato masher in a medium bowl.
- Mix: Mix in the egg, melted butter, salt, sugars, cinnamon, milk, and vanilla using a wooden spoon or electric mixer.
- Spread: Using a rubber spatula, transfer the mixture into a prepared casserole dish and bake for 30 minutes until lightly golden.
- Top: Add marshmallows and streusel, then return to the oven for 20 minutes until bubbly and golden.
- Cool: Let the casserole rest for 10 minutes before serving.
Tips for Making Sweet Potato Casserole With Marshmallows
For extra-smooth sweet potatoes: use a potato ricer instead of a masher.
Roast properly: Make sure the sweet potatoes are very soft before mashing. You can tell they are done when they start releasing juice.
Eggs are essential: The egg gives this casserole its soufflé-like texture, so don’t omit it.
Marshmallow substitute: If mini marshmallows aren’t on hand, chop regular-sized marshmallows and use those instead.
Can I Use Canned Sweet Potatoes or Add Nuts?
Yes, you can make this sweet potato recipe with canned sweet potatoes if desired. Just make sure to drain them really well before mashing them.
If you prefer your sweet potato casserole with nuts, feel free to sprinkle some on top when you add the marshmallows. Pecans and walnuts would both work nicely here.
Make Ahead Instructions
- Bake and mash the sweet potatoes in advance and store in an airtight container in the fridge.
- Prepare the crumble topping ahead of time and freeze in a Ziploc bag for up to a month.
- Assemble the souffle the day before and store in the fridge.
- Bake the casserole on the day you plan to serve it to keep the marshmallows fresh and gooey
This Sweet Potato Casserole can also be frozen ahead of time! Follow all the instructions for making the casserole and freeze it without the marshmallow and streusel topping. When you’re ready to bake it, let it thaw and then add the toppings and bake as directed.
Storing and Reheating
Leftovers should be stored in an airtight container in the fridge and they will keep for up to 5 days.
To reheat leftover sweet potato casserole, you can warm a whole casserole in the oven at 300°F until heated through, or reheat individual servings in the microwave for a quick option. These make the best Black Friday Leftovers!
This is the best sweet potato casserole with marshmallows, and it is incredibly easy to make! With rich, irresistible flavor and a topping that’s both gooey and crunchy, it’s the ultimate holiday side dish that could easily double as a dessert. You’re going to love every bite!
More Thanksgiving Side Dishes:
- Lemon Mandarin Orange Jello Salad
- Southern Grape Salad with Pecans
- Instant Pot Southern Macaroni and Cheese
- Southern English Pea Salad
- Southern Macaroni and Cheese
Don’t Miss This Video
Sweet Potato Casserole
Ingredients
- 3 Medium Sweet Potatoes
- 1 Large Egg
- 1/4 Cup Butter, melted
- 1 Pinch Salt
- 1/4 Cup Granulated Sugar
- 1/3 Cup Brown Sugar
- 1/2 teaspoon Cinnamon
- 1/2 teaspoon Vanilla
- 2 Tablespoons Milk or Heavy Cream, (any milk will do)
Topping
- 2 Cups Mini Marshmallows
- 1/3 Cup Butter, cold and cut in cubes
- 1/2 Cup All-Purpose Flour
- 3/4 Cup Brown Sugar
- 1/2 teaspoon Cinnamon
- 1/2 Cup Panko Bread Crumbs
- 1/4 Cup Graham Cracker Crumbs
Instructions
Make the Casserole
- Preheat the oven to 400 degrees F.
- Place a piece of tin foil on the oven rack.
- Pierce the sweet potatoes with a fork and bake for 45-60 minutes, or until tender.3 Medium Sweet Potatoes
- Carefully peel the potatoes and turn the oven down to 350 degrees F.
- Place the sweet potatoes in a large bowl and smash them until smooth.
- Add the egg, butter, cinnamon, salt, sugars, vanilla and milk.1 Large Egg, 1/4 Cup Butter, 1 Pinch Salt, 1/4 Cup Granulated Sugar, 1/3 Cup Brown Sugar, 1/2 teaspoon Cinnamon, 1/2 teaspoon Vanilla, 2 Tablespoons Milk or Heavy Cream
- Using a handheld or standing mixer, beat everything together until smooth.
- Pour the mixture into an 8×9-inch baking dish (8×8 or 9×9 works too) and bake for 30 minutes.
- Remove from the oven and top with the marshmallows, then the crumb topping (see instructions below on how to make it), making sure to cover the marshmallows as much as possible, and bake for an additional 20 minutes.2 Cups Mini Marshmallows
- Allow to cool for 5 minutes and serve.
Make the Topping
- In a medium sized bowl, add the cold butter, flour, sugar and cinnamon.1/3 Cup Butter, 1/2 Cup All-Purpose Flour, 3/4 Cup Brown Sugar, 1/2 teaspoon Cinnamon
- Using a pastry cutter or fork, cut into the mixture until the butter is well incorporated.
- I like to use my hands at the end.
- Stir in the panko and graham cracker crumbs and set aside until you're ready to top the casserole.1/2 Cup Panko Bread Crumbs, 1/4 Cup Graham Cracker Crumbs
Recipe Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Can I use egg whites instead of regular eggs?
Hi Sol, unfortunately you need whole eggs. 🙁
Is there a substitute I can use for the eggs or can I skip putting the eggs in the sweet potatoes?
Hi Taylor, unfortunately the eggs are needed in this recipe and it wont turn out the same without them. It’s like a soufflé.
I was wondering if you could tell me approximately how much sweet potato mash to use (in cups). I only have access to huge potatoes, and don’t want to use too much, or too little! Thanks!
Hi Anne, ours are usually pretty huge as well so you’re probably fine, but generally one potato is 1 1/2 to 2 cups 🙂
This looks so good! Do you think I could use canned sweet potatoes, or would that mess it up?
Thanks Hilary! You could definitely use canned, but drain it well!
I made this today, and it was delicious!! Everyone loved it. Thanks for the amazing recipe!
Your sweet potato casserole is making my mouth water… I love the marshmallow & brown sugar streusel topping, just beautiful!
Thanks so much Amy!! The whole family just loves it!
This is just straight up delicious!!! I want this on my table for sure!
This is about the only way I can eat sweet potato. 😉
So pretty! I don’t hate marshmallows! Mmmm!
Thanks so much, Julie!
I’m always excited to see new versions of classic family recipes because everyone has their own spin on them. This is great recipe inspiration. Thanks for sharing!
I love it too! I get so sucked into everyone’s modernized recipes and I love it!
I love the topping to sweet potato ratio!!! Delicious!!
Thanks, girl! I’m all about a topping. Notice there are no nuts… yeah the original plan was to use some but rethinking a new nut recipe haha