This Old Fashioned Sweet Potato Casserole brings the perfect blend of sweetness and nostalgia to your holiday table, complete with a gooey marshmallow topping that everyone loves, and best of all only requires five ingredients.

Sweet potato casserole. You either love it or hate it. My family is a bit divided, but for the most part most enjoy my Old Fashioned Sweet Potato Casserole. I love it and the more marshmallows on top the better. Because let’s face it–why else would you eat a homemade sweet potato casserole? As a kid that’s how I was lured to try sweet potato casserole. I’m pretty sure the first few times I had it all I did was eat the crispy marshmallow topping.
When it comes to classic holiday dishes, nothing warms the heart like a sweet potato casserole. Packed with rich, buttery sweetness and crowned with a blanket of toasted mini marshmallows, this dish has been a favorite at family gatherings for generations. It’s the perfect side to complement your Thanksgiving turkey or Christmas ham, and it’s sure to be the star of your holiday spread.
This Old Fashioned Sweet Potato Casserole recipe stays true to tradition while keeping things simple. Made with just a handful of pantry staples like fresh sweet potatoes, butter, brown sugar, cinnamon, and mini marshmallows. Whether you’re a longtime fan of this classic side dish or trying it for the first time, this recipe promises to deliver comfort, flavor, and plenty of holiday cheer.
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Why this Recipe Works
Minimal Ingredients, Maximum Flavor – With just five simple ingredients, this recipe achieves a perfect balance of sweetness, spice, and buttery richness without overwhelming the palate.
Easy to Make Ahead – This casserole is perfect for holiday prep. You can cook the sweet potatoes and assemble the dish a day before you want to bake it, saving you stress on the big day.
Kid-Friendly and Crowd-Pleasing – The toasted marshmallow topping is always a hit, making this dish a favorite among kids (even if they just eat the marshmallows I call it a win at getting them to try something new) and adults alike. It’s guaranteed to disappear fast!
Ingredients

- Sweet Potatoes: The star of the dish. Extra-large sweet potatoes ensure a creamy base with natural sweetness.
- Butter: Adds richness and enhances the flavor of the sweet potatoes. A little goes a long way!
- Brown Sugar: Provides a caramel-like sweetness that pairs perfectly with the natural sugars in the potatoes. You can use more for a sweeter casserole or less to reduce sugar.
- Cinnamon: Adds warmth and depth to the dish.
- Mini Marshmallows: The iconic topping that melts and toasts to golden perfection.
How to Make Sweet Potato Casserole
First, steam sweet potatoes for 20 minutes or until fork tender. Pro Tip: I like to steam my sweet potatoes using the instant pot! This requires not peeling or chopping and saves a lot of time!

Remove from the steamer basket, let rest for 10 minutes, then peel the skins off and place the peeled sweet potatoes into a large bowl.

Add the salted butter, brown sugar, and cinnamon to the bowl.

Using a potato masher, mash the sweet potatoes until smooth.
Preheat the broiler on high.

Spray non-stick cooking spray into an oven-safe 9×11 rectangular baking dish. Pour the mashed sweet potatoes into a dish. I like to sprinkle a little extra brown sugar on top before adding the marshmallows.

Top with mini marshmallows.
Broil on high for 1 minute or until marshmallows are golden brown. Serve immediately.
FAQs

Yes, you can substitute canned sweet potatoes for fresh. Be sure to drain them well before mashing, and adjust the sugar to taste since canned varieties are often sweetened.
Swap out the butter for a dairy-free alternative, such as coconut oil or vegan butter, and double-check that your marshmallows are dairy-free.
Absolutely! Assemble the casserole without the marshmallows, cover, and refrigerate for up to two days. Bring the casserole out to get to room temperature a half hour before baking. Bake with foil on top for a half hour. Then, add the marshmallows on top during the last few minutes of baking. Watch them closely to ensure they don’t burn but stay a nice golden brown in color.
Yes! This recipe is naturally gluten-free as written. However, if you add toppings like crushed graham crackers or other non-marshmallow ingredients, double-check that they’re certified gluten-free.
You can top the casserole with a streusel made from brown sugar, butter, and oats or chopped nuts like pecans for a crunchy, flavorful alternative.
Recipe Tips and Tricks

Here are a few of my favorite tips and tricks to help you execute making a sweet potato casserole.
- Roast the Sweet Potatoes: Roasting sweet potatoes instead of boiling them brings out their natural sweetness and keeps the texture smooth. You can roast the sweet potatoes hole (make sure to prick the skin with the tines of a fork a few times so steam can release) then follow the same steps to peel the skin off.
- Boiling Sweet Potatoes: If you don’t want to steam or roast the sweet potatoes you can peel and dice the sweet potatoes. I don’t like this method as sweet potatoes are harder to peel.
- Toast the Marshmallows Evenly: Place the dish on the middle rack of your oven for even browning, and watch closely to avoid burning.
- Add a Crunchy Topping: If you love texture, sprinkle chopped pecans or crushed graham crackers under the marshmallows for a delightful crunch.
- Balance the Sweetness: Add a pinch of salt to the sweet potato mixture to enhance the flavors and keep it from being overly sweet.
If you make this Old Fashioned Sweet Potato Casserole recipe, I would be honored and love for you to take the time to leave a ⭐ star rating and comment! I spend hours developing and testing these recipes, and always love to hear feedback and user experience!
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Homemade Sweet Potato Casserole
Equipment
- 1 Pot
- 1 Stove
- 1 Knife
- Measuring Spoons
- 1 9×11 Baking Dish
Ingredients
- 8 Sweet potatoes
- 2 tablespoons Salted butter
- ½ cup Brown sugar
- 1 teaspoon Cinnamon
- 4 cups Mini marshmallows
Instructions
- Steam sweet potatoes for 20 minutes or until fork tender.
- Remove from the steamer basket, let rest for 10 minutes, then peel the skins off and place the peeled sweet potatoes into a large bowl.
- Add the salted butter, brown sugar, and cinnamon to the bowl. Using a potato masher, mash the sweet potatoes until smooth.
- Preheat the broiler on high.
- Spray non-stick cooking spray into an oven-safe 9×11 rectangular baking dish. Pour the mashed sweet potatoes into a dish. Top with mini marshmallows.
- Broil on high for 1 minute or until marshmallows are golden brown. Serve immediately.
Notes
- Roast the Sweet Potatoes: Roasting sweet potatoes instead of boiling them brings out their natural sweetness and keeps the texture smooth. You can roast the sweet potatoes hole (make sure to prick the skin with the tines of a fork a few times so steam can release) then follow the same steps to peel the skin off.
- Boiling Sweet Potatoes: If you don’t want to steam or roast the sweet potatoes you can peel and dice the sweet potatoes. I don’t like this method as sweet potatoes are harder to peel.
- Toast the Marshmallows Evenly: Place the dish on the middle rack of your oven for even browning, and watch closely to avoid burning.
- Add a Crunchy Topping: If you love texture, sprinkle chopped pecans or crushed graham crackers under the marshmallows for a delightful crunch.
- Balance the Sweetness: Add a pinch of salt to the sweet potato mixture to enhance the flavors and keep it from being overly sweet.
Cheryl Larimer
With so many dishes to prepare this one will be perfect for us. Gluten free; simple and make ahead. Thanks!
Katie
Thanks Cheryl! Hope you enjoyed it!