This Sweet Potato Casserole with Marshmallows and Pecans will win over even the most averse sweet potato eater. This classic Thanksgiving side dish is made extra special with a delightfully crunchy pecan streusel topping that goes under a gooey marshmallow topping!
Be sure not to miss the rest of our classic Thanksgiving recipes! We always serve this sweet potato casserole with southern cornbread dressing, a fresh green bean casserole (from scratch and so delicious!), and a bacon-roasted turkey that everybody raves about!
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I grew up eating candied yams for Thanksgiving, which is a dish made using chunks of soft, cooked sweet potato topped with butter, brown sugar, and marshmallows. It wasn't ever my favorite dish on our holiday table - probably my least favorite actually, but I have found a new love for sweet potatoes with this easy sweet potato casserole.
Probably the biggest influence in changing my mind about sweet potato casserole is the pecan streusel topping that goes on top. Crunchy pecans add a textural element to the dish that I guess I always wanted or was missing with candied yams. It's the familiar crunch of pecans and crumbly texture of the streusel that make this classic side dish much more interesting, satisfying, and homey for me.
This is the best sweet potato casserole recipe because it takes the holiday classic up a notch by using toasted marshmallows as well as a pecan topping. I also love that actually mashing the sweet potatoes with some cinnamon and brown sugar means you don't get big chunks of in-your-face, unadulterated sweet potato, which just isn't my thing.
Let's be honest here, sweet potato casserole is pretty much an excuse to have sweet potato pie, without the crust, as a side dish at dinner rather than waiting for dessert. That's a decision I can definitely get behind.
While you can make a sweet potato casserole with either the pecan streusel topping OR a pillowy marshmallow topping, I will now always advocate for both. I love the chewiness and the sweet roasted flavor of the marshmallows, and how they combine so well with the crunch of the pecans. Plus, the richness of the cinnamon-spiced mashed sweet potato base is so delicious.
How do you cook sweet potatoes?
You can cook sweet potatoes in the same way that you would any other type of potatoes (boiled, baked, roasted), but for making this sweet potato casserole, I would either boil or roast them. If you are using canned sweet potatoes you may need to adjust the recipe by decreasing the sugar, as they are typically sweeter than fresh sweet potatoes.
I find roasting the easiest method since all you need to do is wash and prick the sweet potatoes with a fork, then bake them in a 350 degree F oven for 45 minutes to an hour until they are soft.
The main advantage of this method is that there is no need to peel or chop the potatoes as the potato becomes so soft, you can just scoop the potato out and make the sweet potato casserole from there. The downside of roasting is that it takes a bit of time and oven space if you don't do this step in advance.
The other method is to boil the sweet potatoes just like you would boil any other potatoes for mashed potatoes. First, peel and wash the sweet potatoes, then cut them into chunks and place them in a large pot. Add enough water to cover them completely and season the water with salt, then bring to a gentle boil for around 10 minutes until they pierce easily with a fork. Be sure to drain them really well before using, otherwise, they will add unwanted liquid to the casserole.
The pro here is a much shorter cooking time, but you have to deal with peeling and chopping.
Why We Love This Recipe
- It's easy to make and uses simple ingredients.
- It combines all the flavors of fall with cinnamon, pecans and toasty marshmallows!
- Easily make a big casserole dish full for
- You can control how sweet you'd like this sweet potato casserole to be, simply omit the marshmallows or add a bit less sugar if you don't want it so decadent.
What You'll Need
Scroll down to the recipe card below this post for ingredient quantities and full instructions.
- Sweet Potatoes - Fresh sweet potatoes are best for this recipe, but you can use canned sweet potatoes in a pinch.
- Salted Butter - To help bind the sweet potato filling as well as make the streusel topping.
- Milk - To give the sweet potato filling a creamy texture and flavor.
- Brown Sugar - Use light brown sugar for a milder flavor, or dark brown sugar for a more intense flavor.
- Cinnamon - For that amazing fall flavor!
- Eggs - Binds the potato filling.
- Vanilla Extract - Adds warmth.
- Salt - For seasoning.
- Chopped Pecans - Adds a crunchy texture.
- Mini Marshmallows - Mini marshmallows work best for this recipe as they are small enough that they will cook through just enough without burning on top, in a short amount of time. If you only have access to large marshmallows you can use them by cutting them into smaller pieces first. Scissors will work best for this, but it will be sticky!
How to Make Sweet Potato Casserole with Marshmallows and Pecans
Cook the sweet potatoes. To roast: Preheat the oven to 350 degrees F. Prick the sweet potatoes all over with a fork, then place them on a baking sheet lined with foil and sprayed with cooking spray. Roast in a 350 degree oven for 45 minutes to 1 hour, until soft. Larger sweet potatoes may take longer to cook. To boil: Peel the sweet potatoes and cut them into chunks, then boil them in a large pot with enough water to cover them for 10 minutes until fork tender rather than roasting them in the oven. Drain well then proceed as directed in the recipe.
Make sweet potato filling. If you have roasted the potatoes, let them cool and scoop out the insides into a large bowl. Alternatively, transfer boiled potatoes straight to a large bowl and gently mash. Add the butter, milk, brown sugar, cinnamon, eggs, vanilla, and salt, and mash with a potato masher or beat using a hand mixer until smooth.
Add potato filling to dish. Spray a 9x13-inch baking dish with cooking spray, then transfer the mashed sweet potatoes to it and smooth them out evenly using a rubber spatula.
Make streusel topping. In a separate bowl, combine the brown sugar, flour, cinnamon, salt, melted butter, and chopped pecans. Mix them together with a fork, then sprinkle over the top of the mashed sweet potatoes.
Bake. Increase the oven temperature to 375 degrees F. Bake the sweet potato casserole for 25-30 minutes, until heated all the way through and the topping begins to brown.
Add marshmallows and broil. Remove the sweet potato casserole from the oven and sprinkle with the marshmallows. Set the oven to broil, then return the casserole to the oven and cook just long enough for the marshmallows to toast on top. Watch carefully as this can happen very quickly, as we all know from our summer campfire marshmallow roasting experiences! Serve immediately.
Yes, this sweet potato casserole can be made in advance, at least in part. You can make the sweet potato filling with the streusel topping assembled in a casserole dish up to 3 days in advance if kept in the refrigerator, or up to 3 months ahead of time if you keep it in the freezer!
For the refrigerator: Cover the dish in plastic wrap, then get it out on the day and heat for 35-40 minutes (rather than the normal 25-30) until heated through and the streusel topping is beginning to brown a bit. Finish with the marshmallows and broil as per the instructions.
For the freezer: It's best to use a foil baking dish as they freeze well and can also go in the oven. Simply assemble the sweet potato filling with streusel layer into a foil baking dish, cover completely and freeze it for up to 3 months. Let it fully defrost in the fridge overnight, then follow the instructions for making it from the fridge.
When you go to the grocery store, the potatoes labeled as yams are actually sweet potatoes. There is more than one variety of sweet potatoes, which can add to the confusion, but the big, long, red-skinned root vegetables with orange flesh inside are sweet potatoes. Yams are not sweet and are more starchy, kind of like a cross between a russet potato and a yucca, with rough, brown, tree-bark-like skin. This article from Bon Appetit does a great job of explaining the differences between the two in more detail.
Store leftovers can in an airtight container or covered in plastic wrap in the refrigerator for up to 4 days. Reheat in the microwave or in the oven.
Tips for Success
- If you worry about burning the marshmallows under a broiler, you could just add them to the casserole and bake a few minutes longer, which gives you a little more leeway without worrying as much about them scorching. But they will also puff up a lot more, which may or may not be a good thing. I personally like to use the broiler.
- Don't skip the eggs in the mashed sweet potato base. They make for a lighter texture, and your sweet potato casserole won't taste eggy at all.
Substitutions and Variations
- Use some maple syrup in place of two tablespoons or so of the brown sugar for an added subtle maple flavor.
- Sprinkle a bit of cinnamon on top of the casserole for added spice.
- If you aren't a fan of mashed sweet potatoes, you could sprinkle the same pecan streusel topping with marshmallows over baked sweet potatoes (just bake, split, and top) and bake them a little longer.
- You can leave out either of the toppings and this casserole would still taste delicious.
- Add some orange juice in with the potatoes, and add some orange zest on top for a citrus twist on this dish.
More Thanksgiving Side Dishes
- Homemade Cranberry Sauce
- Slow Cooker Creamed Corn
- Brussels Sprouts with Bacon & Apples
- Perfect Cornbread
Did you make this recipe?
Let me know what you thought with a comment and rating below. You can also take a picture and tag me on Instagram @houseofnasheats or share it on the Pinterest pin so I can see.
Sweet Potato Casserole with Marshmallows
For the mashed sweet potatoes
- 3 pounds sweet potatoes cleaned (about 3-4 sweet potatoes)
- 4 tablespoons salted butter melted
- ⅓ cup milk
- ½ cup brown sugar
- 1 teaspoon cinnamon
- 2 large eggs lightly beaten
- 1 teaspoon vanilla extract
- ½ teaspoon table salt
For the topping
- ½ cup brown sugar
- ½ cup all-purpose flour
- ½ teaspoon cinnamon
- Pinch of salt
- 6 tablespoons salted butter, melted
- 1 ¼ cups chopped pecans
- 2 cups miniature marshmallows
- Cook the sweet potatoes by roasting or boiling them. To roast: Preheat the oven to 350 degrees F. Prick the sweet potatoes all over with a fork, then place them on a baking sheet lined with foil and sprayed with cooking spray. Roast in a 350 degree oven for 45 minutes to 1 hour, until soft. Larger sweet potatoes may take longer to cook. To boil: Peel the sweet potatoes and cut them into chunks, then boil them in a large pot with enough water to cover them for 10 minutes until fork tender rather than roasting them in the oven. Drain well then proceed as directed in the recipe.
- If you have roasted the potatoes, let them cool and scoop out the insides into a large bowl. Alternatively, transfer boiled potatoes straight to a large bowl and gently mash. Add the butter, milk, brown sugar, cinnamon, eggs, vanilla, and salt, and mash with a potato masher or beat using a hand mixer until smooth.
- Spray a 9x13-inch baking dish with cooking spray, then transfer the mashed sweet potatoes to it and smooth them out evenly using a rubber spatula.
- In a separate bowl, combine the brown sugar, flour, cinnamon, salt, melted butter, and chopped pecans. Mix them together with a fork, then sprinkle over the top of the mashed sweet potatoes.
- Increase the oven temperature to 375 degrees F. Bake the sweet potato casserole for 25-30 minutes, until heated all the way through and the topping begins to brown.
- Remove the sweet potato casserole from the oven and sprinkle with the marshmallows. Set the oven to broil, then return the casserole to the oven and cook just long enough for the marshmallows to toast on top. Watch carefully as this can happen very quickly.
- Serve immediately.
This post was originally published in October, 2018. The photos and content were updated in October, 2022.