Sweet Potato Casserole

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This easy Sweet Potato Casserole recipe is a family favorite that’s loaded with marshmallows, butter, cinnamon. A simple secret ingredient makes this the absolute best sweet potato side dish for Thanksgiving!

Easy Sweet Potato Casserole With Marshmallows

If you ask me, there is only one Sweet Potato Casserole recipe that matters and that is my Mama’s homemade sweet potato casserole with marshmallows!

This old-fashioned casserole is easy to make and can be made a day ahead, making it one of the best Thanksgiving side dishes. I make it every year and our holiday table just wouldn’t be the same without it. Over the years, I have tried many different recipes and this one is by far the best version I have ever tasted.

Sweet potato casserole topped with marshmallows

What’s The Secret To Making The Best Sweet Potato Casserole?

I think it all comes down to that secret ingredient my Mom adds. It comes in a can and is extra creamy. Any guesses what it is?!

Why, it’s sweetened condensed milk of course!

If you have been around here long enough, you know how much my Mom likes to sneak that sweet nectar into recipes. 

Just like in the now famous Mama’s Best Banana Pudding, the sweetened condensed milk adds the perfect sweetness and creaminess to this Sweet Potato Casserole. 

I have tried making this casserole recipe many other ways…like with milk, cream and even evaporated milk. I have also tried regular sugar, brown sugar and maple syrup to sweeten this casserole, but I always come back to using sweetened condensed milk!

Large marshmallows, a cup of spices, cubed butter and diced sweet potato

Recipe Ingredients

There is what you’ll need to make this old fashioned sweet potato casserole:

  • Fresh sweet potatoes
  • Butter
  • Sweetened condensed milk – Our secret ingredient that makes this casserole extra creamy.
  • Spices: cinnamon & nutmeg 
  • Salt
  • Marshmallows

Some people add eggs to their Sweet Potato Casserole and for the life of me I can not figure out why.  To me, when you add eggs, the final product turns out more like a soufflé. It’s just not that classic Thanksgiving casserole that I am personally searching for. 

Sweet Potato Casserole with marshmallows in a white casserole dish

How To Make Sweet Potato Casserole With Marshmallows

Making casserole is easy! Here’s how you do it:

  1. Prepare the sweet potatoes: The first step is to boil our peeled and cubed sweet potatoes in water on the stove until fork tender.
  2. Add butter, condensed milk and spices: Then we add the melted butter, sweetened condensed milk, cinnamon, nutmeg and salt.
  3. Mash everything together: Mash away until smooth and transfer the sweet potato mixture into a greased 9×13 casserole dish.
  4. Top with marshmallows: Load on all those marshmallows on top of the sweet potato casserole. I like to use large marshmallows — just look at that glorious marshmallow to sweet potato ratio — but you can use minis if you prefer. 
  5. Heat in the oven to toast the marshmallows: I bake the casserole at 350°F for a few minutes to make sure everything is hot and to let the marshmallows on top get perfectly toasted.
A fork taking a scoop of sweet potato casserole and a toasted marshmallow from a white plate

Can You Make This Casserole Ahead?

If you want to make this casserole ahead of time, follow all steps but stop right before you put the marshmallows on top. At this point, cover the casserole dish tightly with a lid, cling warp or foil. Then keep it refrigerated until you are getting close to being ready to serve it. 

When you are ready to serve it, take it out of the fridge and let it warm up a little on the counter.

Heat the casserole in oven for 15 minutes (still covered with foil), then remove from oven and carefully top with marshmallows. Then bake it a little longer, uncovered, just until the marshmallows have toasted on top!

This casserole can also sit on the counter for a few hours and wait for your other Thanksgiving side dishes to be ready. Then they can all go into the oven together when you are getting close to eating.

I also included the full make ahead steps and directions in the Sweet Potato Casserole recipe below as well!

Wooden spoon scooping toasted marshmallows off the top of a sweet potato casserole

Other Thanksgiving Recipes You May Like

If you are also on the hunt for the best Thanksgiving dessert recipes, I highly recommend my Sweet Potato Pie, Best Pumpkin Cake, Caramel Apple Dump Cake and Pumpkin Pie Cheesecake

I am so excited to finally be sharing this recipe for my Mama’s famous Sweet Potato Casserole recipe with all of you! I know you and your families/friends are all going to love this amazing recipe.

When you try this recipe, please come back and leave a review/comment below letting me know how it turns out for you!

Yield: 10 - 12 Servings

Sweet Potato Casserole Recipe

Sweet Potato Casserole With Marshmallows Recipe

This easy Sweet Potato Casserole recipe is a family favorite that's loaded with marshmallows, butter, cinnamon and a secret ingredient to create the best Thanksgiving side dish!

Prep Time 25 minutes
Cook Time 15 minutes
Total Time 40 minutes


  • 2.5 lbs sweet potatoes, peeled and diced
  • 8 tablespoons (1 stick) butter, melted
  • 1 (14 oz) can sweetened condensed milk
  • 1 tablespoon cinnamon
  • 1/2 teaspoon nutmeg
  • 1/2 teaspoon salt
  • 1 (16 oz) bag large marshmallows


Preheat oven to 350°F. Spray a 9x13 casserole dish with non stick spray and set aside. 

In a large stock pot, add sweet potatoes and cover with water. Cover pot with lid, bring to a boil and cook until fork tender, about 15 minutes. 

Drain potatoes and transfer back to pot. Add butter, sweetened condensed milk, cinnamon, nutmeg and salt. 

Mash away until nice and smooth. Pour potato mixture into prepared baking dish and smooth out the top.  

Line the top of the casserole with marshmallows and bake until marshmallows are lightly toasted, about 15 to 20 minutes.


Make Ahead Note: If you make this ahead, do not add marshmallows ahead of time. Instead, store the casserole (without marshmallows) in the fridge covered tightly with foil. Heat them in oven for 15 minutes (still covered with foil), then remove from oven and continue on with step #5. 

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Nutrition Information:


12 servings

Serving Size:


Amount Per Serving: Calories: 99Total Fat: 0gSaturated Fat: 0gTrans Fat: 0gUnsaturated Fat: 0gCholesterol: 1mgSodium: 127mgCarbohydrates: 22gFiber: 3gSugar: 8gProtein: 2g


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23 Responses
  1. Lindsey

    Hi Jessica,

    Do you put brown sugar in this recipe? I know it’s not on the ingredient list, but this is my first time making this kind of casserole. Lol

  2. Jennifer

    This looks delicious! I can’t wait to make it. Silly question but I want to be sure; am I buying sweet potatoes or yams? Does it matter? The picture just looks so orange and sweet potatoes to me are whiter? Thank you so much for your help! 🙂

  3. Kathleen Smith

    This was absolutely AMAZING! I also made your green bean casserole I tried this on Thanksgiving and going to make it for Christmas. On my way to the market now to try your caramel apple dump cake. Excellent recipes!

  4. Lora | Savoring Italy

    I love that you use the large marshmallows! Totally agree that it doesn’t need eggs! Perfect for Thanksgiving!

  5. Shelly

    Have a Friendsgiving at work tomorrow. Saw this and ran out and got everything to make it. Stuck a little extra in a little oven crock I had so I could try it before I take it in to work tomorrow. DELICIOUS. So excited now to take this in tomorrow for everyone and it was very easy to make. Thanks!

    1. A woman holding a camera standing in front of some shelves.

      Hi Jennie! I wouldn’t recommend it. Canned sweet potatoes have soaked up a lot of sweetness and moisture from the syrup. So you would have to cut back on a lot of the liquid ingredients to get a decent texture and I can’t guarantee how your final recipe would taste. 

    2. Angel

      Using canned is fine, drain well though. My mom also adds an egg to hers and chopped pecans to help with the texture too. I think she uses two big cans of yams and one small can of sweetened condensed milk and one egg. You may omit the butter though or take it down a smidge. 

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I'm a trial & error, self taught, sugar addict who thankfully learned how to survive in the kitchen! I am also a wife, mama of 3.
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