This sweet potato casserole is the perfect combination of savory & sweet. Soft sweet potatoes are baked under a layer of pecans, brown sugar, and marshmallows.

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Top down view of prepared sweet potato casserole in a white dish with golden brown marshmallows on top.

About Sweet Potato Casserole

When it comes to winter festivities, nothing says holidays and side dishes quite like sweet potato casserole.

I especially love this version of the classic casserole, because the two layers – one being the creamy sweet potato and the other being the flavorful topping – are very defined. The sweet potato mixture is savory with only a touch of sweetness, while the topping is all pecans, sugar, and marshmallow goodness. It gives this casserole a good variety and different flavor profiles while you eat.

Plus, we all know that some people like their sweet potatoes sweet while others like them a little more savory. With this recipe, it’s easy for guests to scoop out the parts they like and leave the rest for someone else. The recipe is also easy to adjust to suit either (or both!) tastes as well.

What’s in sweet potato casserole?

In order to cook up this classic side dish, you’ll need to track down the following ingredients:

  • Sweet potatoes – The star of the show! Their tender texture, bright orange color, and semi-sweet flavor are what make this casserole so popular. But if you ever need a substitution for sweet potatoes, try using an equal portion of garnet potatoes (a type of red potato with a purple hue), pumpkin, butternut squash, or acorn squash.
  • Light brown sugar, salted butter, egg, maple syrup, salt, and vanilla – Classic cooking ingredients that give this casserole its trademark flavor and sweetness. In a pinch, you can substitute the maple syrup for an equal portion of pancake syrup or corn syrup.
  • Chopped pecans – Used for creating the crunchy topping. You can also substitute the pecans for other types of nuts (walnuts, peanuts, almonds, cashews, pistachios, macadamia nuts, brazil nuts, etc) or seeds (sunflower seeds, pumpkin seeds, etc). You could even use cornflakes or granola.
  • Mini marshmallows – The other key ingredient for the topping on this casserole. I found mini marshmallows to get the best coverage, but you could also use standard-sized marshmallows that have been roughly chopped.

Sweet potatoes vs yams

Although sometimes used interchangeably, there are quite a few differences between sweet potatoes and true yams that can impact your cooking. And notice I said “true yams”, as many American grocery stores add to the confusion by labeling some sweet potatoes “yams” despite the fact that true yams are nothing like sweet potatoes at all.

Confused? You and me both!

In short, this is the Cliff Notes version of what’s going on with these potatoes and how to tell them apart:

  • True yams – These are more like a russet sweet potato. They have white flesh with brown scaly skin and a dry, starchy taste. They’re typically grown outside of the United States, making them difficult to find in American grocery stores.
  • Sweet potatoes – A firm sweet potato with golden skin and light or purple flesh. This is the type of sweet potato that was originally grown in the United States.
  • Sweet potatoes that grocery stores call yams – A soft sweet potato with copper skin and golden flesh. Odds are, this is the type of sweet potato you see most often, simply because the soft texture works so well with many of the sweet potato dishes Americans traditionally make. And as for why they’re called yams, it comes down to marketing. The softer sweet potato was the second type of potato grown in the United States, and grocery stores wanted to differentiate this somehow to their customers… and instead of simply calling them firm or soft, they decided to call them yams – a type of potato they are nothing like, but since the “true” form is not commonly sold in the US, the name was seen as “available.”

There are other differences (nutritional value, various names, etc) but the above three points are the ones you need to consider when making substitutions in your cooking.

Given the above, many of the vibrant and sweet-flavored sweet potato dishes you know and love will require just that: a sweet potato (or a vegetable that looks like a sweet potato but has been labeled a yam). A true yam would not have the same bold presentation or flavor that compliments ingredients like brown sugar or maple syrup.

So, in conclusion: always use a sweet potato (or vegetable that looks like a sweet potato but was labeled a yam) when you can, especially if it’s a sweeter dish with ingredients like brown sugar, maple syrup, vanilla, etc (like this casserole)

Close up of sweet potato casserole, showing off pecans and golden marshmallows.

Can you make sweet potato casserole in advance?

Yes, you totally can! You can make this casserole up to 24 hours in advance.

To do this:

  • Follow the recipe instructions up until placing the sweet potato mixture into the baking dish. For best results, hold off on adding the pecans, sugar, and marshmallows until you’re ready to bake.
  • Cover the dish and place it in the refrigerator until ready to bake.
  • Before baking, let the casserole to come to room temperature on the counter, about 30 minutes.
  • Follow the rest of the recipe instructions like normal.

How long is sweet potato casserole good for?

Once prepared and cooled, sweet potato casserole can be stored in a sealed container in the refrigerator for up to four to five days.

Can you freeze sweet potato casserole?

Yes, this casserole can be frozen, but it should be cooked first. There is an egg in this casserole and eggs don’t always fare well when frozen raw.

To freeze a cooked sweet potato casserole, let it come to room temperature, then store in a sealed container or freezer bag. For best results, frozen sweet potato casserole should be eaten within two months.

When ready to eat, let the casserole thaw in the refrigerator overnight. Due to the marshmallows, reheating this casserole in the microwave is probably your best bet.

How long can you leave out a casserole?

Casseroles like this are meant to be enjoyed by a crowd, and when serving, you should always keep track of how long it sits at room temperature.

For most foods, the general rule of thumb is that a perishable item should not be in the “danger zone” for more than two hours. And by “danger zone”, this is usually at or just above room temperature.

Since this casserole will be served warm, that should give you another 30-60 minutes before needing to keep track of the dish. So, in total, this casserole can be left out for an absolute maximum of three hours, depending on the temperature of the room. However, be sure to still check the dish every now and then and make your best judgment.

Once you pass the recommended time, you can heat it up in the oven again.

For best results, I’d recommend using a warming tray so that the sweet potato casserole stays warm and above the “danger zone” temperature.

Notes & tips for sweet potato casserole

  • Don’t like marshmallows? No problem! Marshmallows (as well as the pecans) are an optional topping, so you can completely skip that step if you’d like. Just bake the casserole for 30 minutes total, then serve.
Serving spoon scooping up a portion of sweet potato casserole.

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How to make sweet potato casserole

This next part is only a photo tutorial of the recipe steps. If you’re looking for the full recipe measurements and instructions, scroll down to Recipe Details.

Step 1 – Add the sweet potatoes and water to a dutch oven (or a large stockpot) and boil until tender. Once cooked, drain the water.

Step 2 – In a large bowl, mash the cooked sweet potatoes, brown sugar, butter, maple syrup, salt, and vanilla together until nice and smooth.

Step 3 – Add the potato mixture to a baking dish, then smooth out into an even layer. Cover the top with chopped pecans and more brown sugar.

Step 4 – Bake!

Step 5 – Remove the casserole from the oven and sprinkle some mini marshmallows on top.

Step 6 – Bake again until the tops of the marshmallows turn a pretty golden brown.

Step 7 – Serve and enjoy!

Recipe Details

Top down view of prepared sweet potato casserole in a white dish with golden brown marshmallows on top.
4.80 from 5 votes

Sweet Potato Casserole

15 minutes prep + 50 minutes cook
386 kcal
Yields: 8 servings
This sweet potato casserole is the perfect combination of savory & sweet. Soft sweet potatoes are baked under a layer of pecans, brown sugar, and marshmallows.



  • Preheat oven to 375 degrees F. Spray a 9×13 baking dish with cooking spray, then set aside.
  • Place sweet potatoes in a Dutch oven (or a deep stockpot) and cover with water. Bring to a boil, then reduce heat to a simmer for 15 minutes or until potatoes are very tender. Drain water and let potatoes cool slightly (TIP: place cooked sweet potatoes in the refrigerator to speed things up).
    2 1/2 pounds sweet potatoes
  • In a large bowl, add potatoes, 3/4 cup brown sugar, butter, egg, maple syrup, salt, and vanilla. Mash all ingredients together with a potato masher until mostly smooth.
    1 cup light brown sugar, 1/4 cup salted butter, 1 egg, 2 tablespoons maple syrup, 1 1/2 teaspoons salt, 1/2 teaspoon vanilla extract
  • Pour sweet potato mixutre into prepared baking dish and smooth into an even layer.
  • Sprinkle chopped pecans and remaining 1/4 cup bown sugar on top of potato mixture.
    1/2 cup chopped pecans, 1 cup light brown sugar
  • Bake casserole, uncovered, for 25 minutes.
  • Remove casserole from oven, then sprinkle mini marshmallows evenly across the top.
    2 cups miniature marshmallows
  • Return the casserole to the oven for another 5-10 minutes or until top of marshmallows begin to turn golden brown.
  • Serve immediately.


Serving: 1serving | Calories: 386kcal | Carbohydrates: 70g | Protein: 4g | Fat: 11g | Saturated Fat: 4g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 4g | Trans Fat: 1g | Cholesterol: 36mg | Sodium: 591mg | Potassium: 564mg | Fiber: 5g | Sugar: 43g | Vitamin A: 20321IU | Vitamin C: 3mg | Calcium: 81mg | Iron: 1mg

I do my best to provide nutrition information, but please keep in mind that I’m not a certified nutritionist. Any nutritional information discussed or disclosed in this post should only be seen as my best amateur estimates of the correct values.

Author: Chrisy