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Win over even the most averse sweet potato eaters this Thanksgiving with this Sweet Potato Casserole with Marshmallows and Pecans. It’s a family favorite holiday classic that is made even more delightful with both a crunchy pecan streusel topping and toasted marshmallows on top!

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! 

sweet potato casserole with marshmallows in a white baking dish with a spoon scooping some out of the pan

Sweet Potato Casserole with Marshmallows and Pecans

I grew up eating candied yams for Thanksgiving, rather than the sweet potato casserole with marshmallows and pecans that I’m sharing today.

And to be honest, I just never really loved the candied yams like it seemed everyone else did, despite the fact that I felt like I SHOULD like them. Like, what is wrong with a child who says no to anything topped in butter and sugar and marshmallows? Because that’s what candied yams are, just chunks of soft, cooked sweet potato, topped with butter, brown sugar, and marshmallows. The ingredients are really similar to sweet potato casserole, but I love the latter while I really just am not that big of a fan of the former.

When I discovered sweet potato casserole, I was hesitant to try it, given my usual apathy bordering on outright distaste toward Thanksgiving sweet potato dishes. But once I tried it I was instantly hooked. Suddenly this went from one of my least favorite Thanksgiving side dishes to one of my top choices.

An image of a pan of classic sweet potato casserole with marshmallows.

And it’s not just me. We had friends over for dinner to help us eat this sweet potato casserole and the husband had similar feelings to mine, but had changed his tune thanks to a few important differences between the two dishes.

Probably the biggest influencer in my adoration of sweet potato casserole is because of the pecan streusel topping that goes on top. It adds 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 makes it much more satisfying, homey, and interesting for me.

I also love that actually mashing the sweet potatoes with some cinnamon and brown sugar means you don’t get big chunks of straight in your face, unadulterated sweet potato, which just isn’t my thing. I don’t mean to hurt any feelings for those sweet potato obsessed individuals who enjoy them on the reg, but I’m a lot happier when they are in pie form.

And 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 sweet potato casserole with either the pecan streusel topping OR marshmallows, I advocate for both because I love the almost chewiness and roasted flavor the marshmallows give and how it combines with the crunch of the pecans and richness of the cinnamon spiced mashed sweet potato base.

An image of a scoop of Thanksgiving sweet potato casserole with marshmallows toasted on top of a pecan streusel topping.

What is the difference between yams and sweet potatoes?

When you go to the grocery store, what might be labeled as yams are actually sweet potatoes.

There is more than one variety of sweet potato, which can add to the confusion, but the big, long red-skinned root vegetables with orange flesh inside? Those are definitely sweet potatoes, not yams, which are actually not sweet and more starchy, kind of like a cross between a russett potato and yucca, with rough, brown, tree-bark like skin.

This article from Bon Appetit does a great job of explaining even more thoroughly about the differences between the two, if you care to know more.

How do you cook sweet potatoes?

The two main methods I have used for cooking sweet potatoes to use in sweet potato casserole are to boil or roast them. You could use canned yams if you really needed to, but they are typically sweeter, so you might need to adjust the recipe a bit by decreasing the sugar.

I think roasting is the easiest method since all you need to do is wash and prick the sweet potatoes with the tines of a fork, then bake them in a 350 degree F oven for 45 minutes to an hour until they are soft.

The main pro with this approach is that there is no need to peel or chop the sweet potatoes, since it is easy to scoop out the soft flesh inside and make the sweet potato casserole from there.

The con is that it takes longer and takes up oven space if you don’t do this step in advance.

An image of sweet potatoes in their skins on a pan for roasting in the oven.
An image of baked sweet potatoes that have been scooped out of their skins and into a bowl for mashing.

The other method is boil the sweet potatoes just like you would boil any 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.

How to Make Sweet Potato Casserole with Marshmallows and Pecans

Regardless of which cooking method you choose for your sweet potatoes, once they are tender, all you need to do to make the sweet potato part of this dish is to mash or whip the soft sweet potatoes with butter, milk, brown sugar, eggs, vanilla, cinnamon, and salt. Then spread the mashed sweet potato filling into the bottom of a 9×13-inch baking dish in an even layer.

An image of the ingredients for sweet potato casserole in a bowl for mashing.
An image of mashed sweet potatoes with brown sugar, milk, butter, and cinnamon in a serving dish, ready to be topped with marshmallows for sweet potato casserole.

Next, top the mashed sweet potatoes with an easy pecan streusel made by combining brown sugar, flour, melted butter, cinnamon, salt, and pecans in a medium bowl and mixing them together with a fork.

Sprinkle the streusel evenly over the sweet potatoes, then bake the casserole in a 375 degree F oven until hot all the way through and the topping is just beginning to brown (around 25-30 minutes). Switch the oven to broil, then top the sweet potato casserole with marshmallows and stick it back in the oven under the broiler just long enough to toast the marshmallows.

Be very careful to watch so they don’t burn, which can easily as we all know from our summer campfire marshmallow roasting experiences.

An image of a scoop of brown sugar and cinnamon sweet potato casserole with marshmallows and pecans for Thanksgiving dinner.

Can You Make Sweet Potato Casserole Ahead of Time?

Yes, this sweet potato casserole can be made in advance, at least in part. The first steps of cooking the sweet potatoes, combining them with the other filling ingredients and mashing, then spreading in a baking dish and topping with the streusel topping can all be done up to 3 days in advance.

Just be sure to cover the unbaked casserole and keep it in the fridge. Then on the day you want to serve the sweet potato casserole, just pull it out of the fridge and heat for 35-40 minutes, rather than the normal 25-30, until heated throughout and the streusel topping is beginning to brown a bit. Finish with the marshmallows as you normally would.

An image of a hand holding a serving spoon to scoop out a portion of mashed sweet potato casserole with pecan praline topping and toasted marshmallows.

Tips for Sweet Potato Casserole

  • If you have nut allergies or don’t like marshmallows, you could leave either part off the sweet potato casserole and it would still taste delicious.
  • 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.
  • If you REALLY aren’t a fan of mashed sweet potatoes, you could sprinkle the same pecan streusel topping and marshmallows over baked sweet potatoes (just bake, split, and top) and bake them a little longer.
An image of a scoop of Thanksgiving sweet potato casserole with marshmallows toasted on top of a pecan streusel topping.

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sweet potato casserole with marshmallows in a white baking dish with a spoon scooping some out of the pan
Yield: 10 servings

Sweet Potato Casserole with Marshmallows

Win over the most averse sweet potato eaters this Thanksgiving with this Sweet Potato Casserole with Marshmallows and Pecans.  It's a family favorite holiday classic that is made even more delightful with both a crunchy pecan streusel topping and roasted marshmallows on top!

Prep Time 20 minutes
Cook Time 1 hour 30 minutes
Total Time 1 hour 50 minutes


For the mashed sweet potatoes

  • 3 pounds sweet potatoes, cleaned (about 3-4 sweet potatoes)
  • 4 tablespoons butter, melted
  • 1/3 cup milk
  • 1/2 cup brown sugar
  • 1 teaspoon cinnamon
  • 2 eggs, lightly beaten
  • 1 teaspoon vanilla
  • 1/2 teaspoon salt

For the topping

  • 1/2 cup brown sugar
  • 1/2 cup flour
  • 1/2 teaspoon cinnamon
  • pinch of salt
  • 6 tablespoons butter, melted
  • 1 1/4 cups chopped pecans
  • 2 cups miniature marshmallows


  1. Preheat the oven to 350 degrees F.  Prick the sweet potatoes all over with the tines of 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.
  2. Let the sweet potatoes cool enough to easily handle them, then scoop out the insides into a large bowl (if using roasted sweet potatoes).  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.
  3. 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.  
  4. 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.  
  5. 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.
  6. 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.
  7. Serve immediately.  Leftovers can be stored in an airtight container.


If you prefer, you could peel the sweet potatoes and cut them into chunks, then boil 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.

Nutrition Information:



Amount Per Serving: Calories: 469Saturated Fat: 8gCholesterol: 63mgSodium: 321mgCarbohydrates: 64gFiber: 5gSugar: 33gProtein: 5g