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! 

Sweet potato casserole with marshmallows in a white baking dish with a spoon scooping some out of the pan.
Table of Contents
  1. How do you cook sweet potatoes?
  2. Why We Love This Recipe
  3. What You'll Need
  4. How to Make Sweet Potato Casserole with Marshmallows and Pecans
  5. Recipe FAQs
  6. Tips for Success
  7. Substitutions and Variations
  8. More Thanksgiving Side Dishes
  9. Sweet Potato Casserole with Marshmallows Recipe

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.

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

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.

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

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.

An image of sweet potatoes in their skins on a pan for roasting in the oven.

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.

An image of baked sweet potatoes that have been scooped out of their skins and into a bowl for mashing.

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.

An image of the ingredients for sweet potato casserole in a bowl for mashing.

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.

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.

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.

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

Recipe FAQs

Can You Make Sweet Potato Casserole Ahead of Time?

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.

Are yams and sweet potatoes the same?

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.

How do I store this casserole?

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.

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

More Thanksgiving Side Dishes

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.

Stay in the know

Sweet Potato Casserole with Marshmallows

5 from 36 votes
Amy Nash
Prep Time 20 mins
Cook Time 1 hr 30 mins
Total Time 1 hr 50 mins
Course Side Dish
Cuisine American
Servings 10 servings
This Sweet Potato Casserole is made extra special with a delightfully crunchy pecan streusel topping that goes under a gooey marshmallow topping!

Ingredients
  

For the mashed sweet potatoes

  • 3 pounds sweet potatoes cleaned (about 3-4 sweet potatoes)
  • 4 tablespoons salted butter melted
  • 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

Instructions
 

  • 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.

Video

Notes

Make-ahead instructions: 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!
Storage instructions: Leftovers can be stored in an airtight container in the refrigerator for up to 4 days. Reheat in the microwave or in the oven.

Nutrition

Calories: 469kcal | Carbohydrates: 64g | Protein: 6g | Fat: 22g | Saturated Fat: 9g | Polyunsaturated Fat: 4g | Monounsaturated Fat: 9g | Trans Fat: 1g | Cholesterol: 64mg | Sodium: 321mg | Potassium: 579mg | Fiber: 6g | Sugar: 34g | Vitamin A: 19724IU | Vitamin C: 3mg | Calcium: 90mg | Iron: 2mg
Tried this recipe? Show me on Instagram!Mention @HouseOfNashEats or tag #houseofnasheats!

This post was originally published in October, 2018. The photos and content were updated in October, 2022.

Share This With the World

PinYummly

Related Recipes

About the author

Hi, I'm Amy

I enjoy exploring the world through food, culture, and travel and sharing the adventure with mostly from-scratch, family friendly recipes that I think of as modern comfort cooking.

Leave a comment

Your email address will not be published.

How many stars would you give this recipe?




This site uses Akismet to reduce spam. Learn how your comment data is processed.

Reader questions and reviews

  1. 5 stars
    What a yummy looking dish!! It reminds me of Thanksgiving at grandma's but without the pecan topping. I LOVE that you can do the prep work for this dish up to two days in advance and finish it off in the oven like a casserole. Anything that reduces the amount of work on Thanksgiving is a good thing in my book!

  2. 5 stars
    I am one that loooooves the candied yam dish but after going to college and having my roommates mom's sweet potato dish, it opened my eyes to start trying new sweet potato dishes for Thanksgiving! I'm definitely going to be making it this year for my Thanksgiving dinner!

  3. 5 stars
    Yummm this looks delicious! I will take any kind of sweet potato side dish at Thanksgiving!! I love a more savory one AND one like this with streusel and marshmallows, so I'm happy when both show up at our family dinner.

  4. I just finished making this and it turned out perfectly. For anyone worried about measurements. The recipe ingredients list already separates and categorizes which measurements go for which stage. There's a topping stage and a base stage. The directions were good and it turned out amazing. I added a little nutmeg for that autumn holiday taste! You can go a little easy on the brown sugar if needed if you dont want it to be super sweet. Enjoy.

    1. Thank you for the idea to add nutmeg. Also, good idea on decreasing the amount of sugar. I have found that many dishes are just as sweet with less than the sugar that is called for in the recipe. I hope you make it again this year! I will be trying it for the first time! Happy Thanksgiving! 

  5. This looks great I have to cook the entire dinner and was wondering would this turn out the same using canned sweet potatoes

  6. How do you sprinkle the streusel topping when it’s solid mixture all stuck together by the butter.  I was confused I had to use a spatula to spread that part. 

  7. Looks good but I have to take it someplace is there anyway where I can cook it then keep it warm in a bag the at the other place add marshmallows and broil it?

  8. Hello! I am asking this last minute so I really hope you see this and respond asap, but if not I understand! I am doubling the recipe, but am wondering if I should double the eggs. Or if there is anything else I shouldn't fully double. Thank you and thanks for sharing what looks to be a yummy recipe 🙂

    1. I try to aim for around 3 pounds of sweet potatoes which is about 3-4 sweet potatoes. I usually get pretty averaged size sweet potatoes. If you get pretty big ones you could probably just do three but if they are on the smaller size, do 4-5. But, I will say it's a pretty forgiving recipe and will come out delicious no matter what!

      1. Hi Susan. You could do two cans of yams for the casserole. Just make sure you drain it really well! Just mix the canned yams with the butter, milk, brown sugar, cinnamon, eggs, vanilla, and salt, and mash with a potato masher or beat using a hand mixer until smooth.

  9. 5 stars
    I made this last year and it’s wonderful. I can’t remember, To make ahead I follow all the instructions but I never put it in the oven until the day of. Correct?

    1. 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. 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.

  10. How long is baking time if you are doubling up recipe? Can I cut the potatoes into cubes the night before?

    1. Should be the same bake time, although you might need an extra 5-10 minutes. Yes, you can cut the potatoes the night before and they should be just fine.

  11. 5 stars
    Best sweet potato casserole recipe ever! I do not like sweet potato casserole and therefore when I make it, I’m not tasting it to see what it needs or if it is any good. Yet somehow I’m always the one asked to make this. I found this recipe Tuesday and bought everything except pecans. I already had walnuts and used those instead of pecans. Literally everyone raved about this being the best sweet potato casserole they have ever had and now I’m the one they want making this every year for Thanksgiving and Christmas. Thank you! It’s simple and a definite hit in our family!

    1. I literally called my husband over to read your comment, Kelli. We were both saying that this is how we always felt about sweet potato casserole too! I didn't like it at all growing up by now it's one of my favorite things and it's all because of this recipe! So glad it was a hit!