Classic Sweet Potato Casserole with Marshmallows

This classic sweet potato casserole is topped with mini marshmallows and made with only 6 ingredients. It’s creamy, delicious and the perfect side dish for Thanksgiving.

Sweet potato casserole in a square baking dish with a portion missing in the corner where a metal spoon is.

Sweet potato casserole has always been my favorite dish! My mom made it at least three times a year growing up and I was always a huge fan. Her version has a brown sugar pecan topping, which I recreated with my healthy sweet potato casserole, but Isaac grew up with traditional sweet potato casserole with marshmallows on top.

Without fail, every year Isaac requests the classic version so I finally decided to give it a go and… whoa, it turned out to be so delicious! I am honestly kind of surprised at how much I liked this sweet potato casserole recipe. Usually I’m all about the crunch of the pecan topping. That said, the marshmallows actually get a little crisp with this version so maybe that’s why I’m a fan.

Why I Love This Recipe

  • Easy to make – With just 6 simple ingredients, this recipe is straightforward and hassle-free, perfect for beginners or those looking for a quick and easy holiday side dish.
  • Delicious – The combo of creamy sweet potatoes with a gooey marshmallow topping = chef’s kiss!
  • Crowd-pleaser – This is a classic holiday side dish that is loved by both adults and kids! I usually serve it for Thanksgiving dinner. It’s the perfect side to serve alongside my air fryer turkey breast, sourdough stuffing, healthy cranberry sauce, glazed carrots and shaved brussels sprouts salad.
  • Make in advance – You can prepare this recipe up to 3 days in advance.

Ingredients Needed

Ingredients measured out to make Classic Sweet Potato Casserole: marshmallows, butter, sea salt, coconut or brown sugar, sweet potatoes and vanilla.
  • sweet potatoes – the star ingredient, providing natural sweetness and a creamy texture. When shopping for sweet potatoes, look for firm, unwrinkled skins with deep orange flesh. I usually buy Beauregard, Jewel or Garnet sweet potatoes just because those varieties are typically available at my local grocery stores. That said, Beauregard sweet potatoes tend to be stringier so when given the option I go for Jewel or Garnet.
  • coconut sugar or brown sugar – the perfect sweetener adding a rich depth of flavor to the sweet potatoes and a nice molasses flavor.
  • unsalted butter – helps to keep this casserole moist while binding the sweet potato filling together.
  • vanilla extract – the perfect flavor enhancer. Be sure to use pure vanilla extract and not imitation vanilla for the best results.
  • mini marshmallows – adds sweetness and a delicious gooey topping. Miniature marshmallows work best for this recipe, but you can use large marshmallows if that’s all you have on hand. You’ll just want cut them into smaller pieces before using.

Find the full ingredient list with measurements in the recipe card below.

Recipe Substitutions

  • Make it vegan: Since this recipe doesn’t have any eggs, milk or heavy cream you can easily make it vegan by using vegan butter and vegan marshmallows like these Dandies mini marshmallows.
  • Add pecans: If you’re like me and love pecans, you can sprinkle 1/4 cup pecans on top of the sweet potato mixture with the marshmallows.
  • Add cinnamon: For some spice and added warmth sprinkle some ground cinnamon on top of the casserole.

How to Make Sweet Potato Casserole

Four large sweet potatoes on a baking tray.

Step 1: Use any of the methods listed below to cook your sweet potatoes.

A fork is used to mash sweet potatoes in a large bowl.

Step 2: Once your sweet potatoes are fork-tender peel and transfer the flesh to a large bowl. Use a fork or potato masher to mash the sweet potatoes until smooth and creamy.

Mashed sweet potato sugar, salt, butter, and vanilla in a large glass bowl.

Step 3: Add sugar, butter, salt and vanilla to the potatoes and stir to combine.

Sweet potato casserole in a square baking dish.

Step 4: Transfer mixture to a baking dish, top with marshmallows and bake for 20-25 minutes at 375ºF .

Brittany’s Tips!

  • Browning the marshmallows: If you want to brown your marshmallows more you can broil for a few minutes at the end of baking. Just keep a close eye on the dish to prevent the marshmallows from burning!
  • Double the recipe: To serve a larger crowd you can easily double this recipe and bake it in a 9×13 baking dish.
A spoon taking a small portion of sweet potato casserole from a square baking dish.

How to Cook Sweet Potatoes

There are many different ways you can cook your sweet potatoes for this recipe. Here are some ideas:

  • Bake – Pierce the sweet potato 4-6 times with a fork. Place potato on a baking sheet and bake at 400ºF for about 45-65 minutes.
  • Boil – Peel and cube the sweet potatoes. Place in a large pot and add water to cover the potatoes. Bring to a boil, reduce heat and cook, uncovered until tender. It should take about 15 minutes depending on the size.
  • Microwave – Pierce the sweet potatoes 3-4 times with a fork. Place potatoes in a microwave-safe dish and microwave on high for five minutes, flipping halfway through. If your potatoes aren’t tender after 5 minutes, microwave for 30 second increments until softened. I personally don’t recommend this method because microwaved sweet potatoes don’t taste great, in my opinion.
  • Instant Pot – Add one cup of water to the bottom of your Instant Pot. Place the trivet on top and then the sweet potatoes on the trivet. Cook for 18 minutes on high pressure (for medium-sized potatoes), let naturally steam naturally release for 10 minutes and then quick release any remaining pressure.

How to Make in Advance

You can certainly prep this sweet potato casserole ahead of time to make things easier for holiday meals!

  • One option is to cook your sweet potatoes in advance. Once cooked, let cool and store in the fridge for up to 3 days before making the casserole.
  • Another option is to prep the recipe according to the instructions through step two, cover the casserole dish with foil or plastic wrap and keep in the fridge for 1-2 days. On the day of serving, bring the dish out and let it come to room temp (about 10-15 minutes), top with marshmallows and bake in a 375°F oven for 20-25 minutes or until potatoes are warm and marshmallows are golden brown.
A serving of sweet potato casserole in a small bowl with a metal spoon.

How to Store Leftovers

If you find yourself with leftovers, this casserole stores well in the refrigerator. Simply cover the dish with plastic wrap or aluminum foil and place in the fridge for 3-4 days. To reheat, simply place the baking dish back into the oven at 350°F for about 10-15 minutes, or until warmed through.

Note! The marshmallows will slowly melt into the sweet potatoes as they sit in the fridge. The dish will still taste delicious and you can always add more marshmallows on top before reheating.

Frequently Asked Questions

Can you freeze sweet potato casserole?

I don’t normally freeze leftovers because we get through them so quickly, but you can certainly freeze this sweet potato casserole if you want. I would just recommend that you only prepare the sweet potato filling to freeze.

Bake it according to the directions without the mini marshmallows on top, then let it cool completely, cover with foil and freeze for up to 3 months. When you’re ready to enjoy, let the casserole thaw in the fridge overnight then top it with marshmallows and reheat in the oven until marshmallows are golden and the casserole is warm.

Is it better to boil or bake sweet potatoes for sweet potato casserole?

The method used to cook your sweet potatoes is totally a personal preference. I love the flavor baked sweet potatoes add to this dish, but I’ve also boiled them before and both have turned out awesome. You can also cook your potatoes in an Instant Pot or in the microwave if you’re short on time!

What is the difference between sweet potato and yam?

Many grocery stores use the terms “yam” and “sweet potato” interchangeably, but the two are actually quite different. Real yams have rough brown skin, starchy white flesh and a long, cylinder shape. Sweet potatoes usually have smooth, thin orange skin with orange, white or purple flesh. They’re shorter and wider than yams and have a much sweeter taste.

Even if you buy a “yam” at the grocery store you’re more than likely actually buying a sweet potato as yams aren’t widely available at grocery stores throughout the U.S.

More Sweet Potato Recipes to Try:

Check out all of my sweet potato recipes and the full collection of Thanksgiving recipes here on EBF.

If you enjoyed this recipe, please consider leaving a ⭐ star rating and let me know how it went in the 📝 comments below.

  • Heat oven to 400°F. Pierce sweet potatoes with a fork several times. Place sweet potatoes on baking sheet. Roast 1 hour or until tender. Let cool and remove skin from the sweet potatoes and discard.

  • Place flesh into large bowl, mash with a fork or potato masher and measure 6 cups. Save any extra for another use. Reduce oven temperature to 375° F.

  • Add sugar, softened butter, salt and vanilla to the sweet potatoes. Stir to combine. You can use a hand mixer or stand mixer for this if you’d like.

  • Transfer sweet potato mixture to a 9 x 9-inch baking dish coated with cooking spray. Use a spoon to make sure the mixture is evenly distributed. Top with marshmallows.

  • Bake for 20-25 minutes or until marshmallows are golden. Serve warm.

  • Boil sweet potatoes: You can also boil the sweet potatoes if you prefer. To do so, peel and cube sweet potatoes. Place in a large saucepan; add water to cover. Bring to a boil. Reduce heat; cook, uncovered, until tender, 15 minutes, depending on size. Drain potatoes, mash and measure 6 cups for the recipe.
  • To store: Let the casserole cool completely, then cover with plastic wrap or aluminum foil and place in the fridge for 3-4 days. To reheat, simply place the baking dish back into the oven at 350°F for about 10-15 minutes, or until warmed through.
  • To freeze: Bake the casserole according to the directions without the mini marshmallows on top, then let it cool completely, cover with foil and freeze for up to 3 months. When you’re ready to enjoy, let the casserole thaw in the fridge overnight then top it with marshmallows and reheat in the oven until marshmallows are golden and the casserole is warm. 

Serving: 1 | Calories: 135kcal | Carbohydrates: 28g | Protein: 1g | Fat: 3g | Saturated Fat: 2g | Polyunsaturated Fat: 1g | Cholesterol: 8mg | Sodium: 159mg | Fiber: 1g | Sugar: 15g

Nutrition information is automatically calculated, so should only be used as an approximation.

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