Boston Market Sweet Potato Casserole is one side dish that absolutely steals the show. Check out my video in this post just to see how outstanding it looks! Lusciously creamy with a decadent streusel topping, it’s seasoned with spices that just scream “holiday.” But rest assured – you can make this delicious, marshmallow-topped Boston Market sweet potatoes recipe any day, any time, anywhere!
Boston Market Sweet Potato Casserole
This copycat Boston Market sweet potato recipe combines a rich sweet potato mixture with brown sugar streusel topping and mini marshmallows. It’s popular for a good reason!
Difference Between Sweet Potatoes and Yams
Even though you will see labels for yams and sweet potatoes, what you find at the grocery store is typically two different varieties of sweet potato.
One will have lighter skin and pale yellow flesh, while the other will have darker skin with deep orange flesh.
Either will work just fine in this southern sweet potato casserole.
Making Sweet Potato Casserole With Marshmallows
- Cook the potatoes.
Start by boiling the sweet potatoes until you can easily pierce them with a fork. Then place them into a colander in the sink to drain the water out.
- Add back to the cooking pot.
The heat from the pot will help absorb any excess water. Then add and mix in the sugar, butter, cream, and spices until everything is creamy and smooth.
- Transfer to baking dish and bake!
Then, smooth the sweet potato mixture into a greased baking dish and top with marshmallow and streusel.
Bake until the top is golden and crispy. It’s that simple!
Ingredient Notes & Substitutes
- Sweet Potatoes – The small and medium sized spuds tend to be the sweetest, so keep an eye out for ones around that size with little to no blemishes.
Larger potatoes are usually starchier – and that’s not what we want!
- Light Brown Sugar – Brown sugar melds with the flavors of sweet potatoes much better than white granulated sugar.
Its deep, molasses-like sweetness is so incredible in this buttery, creamy casserole! Dark brown sugar works as well.
- Heavy Cream – For that characteristic creaminess! Half and half or whole milk could work, too, but won’t add quite the same texture.
- Ground Cinnamon & Nutmeg – I can almost smell and taste these seasonings just by thinking about them!!
As far as substitutes go, your best options are allspice and cloves. Both are well suited for these colder months – they’ll warm you right up!
- Mini Marshmallows – And I do mean mini, please!
Smaller marshmallows will toast and fluff up just fine, while larger ones will give you more of a droopy, sticky mess.
- Old Fashioned Rolled Oats – Our streusel is built on these tasty grains. It’s like an oatmeal cookie!
Don’t use instant oats – they’re over-processed, thin, and will make the casserole mushy.
- Nuts or not, Boston Market Sweet Potato Casserole hits the spot!
Substitute chopped pecans for rolled oats, or use a mix of both!
- Double the recipe to feed a crowd!
You can easily double the sweet potato casserole recipe if needed.
Bake it in two separate 9×13-inch casseroles dishes, or a 4 quart casserole dish, so it doesn’t bubble over.
Tips For A Perfect Copycat Boston Market Sweet Potatoes Recipe!
- Make It Dairy Free – The heavy cream can be substituted with coconut cream (the thick, creamy portion found at the top of full-fat coconut milk) or a plant-based milk.
Swap out the butter with plain ol’ margarine or another plant based butter substitute!
- Can You Use Canned Sweet Potatoes? You absolutely can! Just drain them, rinse the syrup off, and mash them up.
You’ll need 8 cups of mashed sweet potatoes for this Boston Market sweet potatoes recipe.
- Cook The Potatoes All The Way Through – Undercooked potatoes will totally sabotage your casserole!
Be sure to bake them until they’re fork tender – trust me, everyone would rather wait a couple of extra minutes for a super creamy casserole than get a lumpy, starchy mess earlier.
- Try Frozen Potatoes! You can find sweet potatoes pre-skinned and cubed among the frozen veggies at the grocery store.
If you can snag them, do it! Those will be the ripest and sweetest potatoes around. Let them thaw in the fridge and then come to room temperature before using.
Prep Ahead Instructions
Because we’re not using eggs, this recipe is completely safe to prepare up to 3 days ahead of time! Talk about convenient!
Boil and mash your sweet potatoes the day before baking.
Season and store in the dish, either with a lid or tightly wrapped in plastic or foil, and refrigerate until a couple of hours before baking.
Set the dish out to come to room temperature before adding the streusel and marshmallows. Then, bake as usual!
This will really cut down on time and work for you on the day of!
If you’re making multiple portions and doubling up this sweet potato casserole with marshmallows, then I recommend doing so in two separate casserole dishes or using a larger 4-quart dish so that it doesn’t bubble over.
To see this sweet potato side dish made from start to finish, watch the video! Look for it in the recipe card, at the bottom of this post.
Storing and Reheating Sweet Potato Casserole With Marshmallows
I can’t imagine you’ll have any leftovers! But if you do, then you’ll want to keep this covered and chilled for up to 5 days.
You can reheat your Boston Market sweet potato casserole in the oven at 350°F or give individual portions a few 30-second trips in the microwave.
Boston Market Sweet Potato Casserole FAQ
The original recipe does, but this one does not! I replaced the pecans in the streusel topping with rolled oats.
You can certainly add them back into the mix if you’d like, or try a combination of the two!
The yam is like the tough cousin of the sweet potato. It is in fact a kind of sweet potato, but a dry and starchy kind. It has a light skin and yellow flesh.
The sweet potato that we know and love is sweeter, has a softer flesh, and a reddish tinge.
But you know what? Either will do!
The original Boston Market sweet potato casserole has 448 calories per serving.
While my copycat comes very close to what you’d get at the restaurant, calories always vary depending on the specific ingredients that you choose. So consider the calorie count of your own ingredients when preparing this recipe!
With love, from our simple kitchen to yours.
Other Popular and Easy Holiday Sides
Boston Market Sweet Potato Casserole + Video
- 4 pounds sweet potatoes, peeled and cut into 1” pieces
- 4 tablespoons unsalted butter, 1/2 stick
- 3/4 cup packed light brown sugar
- 1/2 cup heavy cream
- 1 teaspoon kosher salt
- 1 tablespoon pure vanilla extract
- 1 teaspoon ground cinnamon
- 1/4 teaspoon ground nutmeg
- 2 cups mini marshmallows
- 1/2 cup all-purpose flour
- 4 tablespoons unsalted butter
- 6 tablespoons packed light brown sugar
- 1/4 cup old fashioned rolled oats, not instant oats
- 1/4 teaspoon ground cinnamon
- Preheat the oven to 350°F. Grease an 8”x10” casserole dish (8×8 or 9×9 works too).
- Fill a large pot with sweet potato pieces and enough water to cover by 2 inches. Bring to a boil over high heat and cook until fork tender, about 10 minutes.
- Drain water from potatoes and return potatoes to the pot. Using a potato masher or electric mixer, mash until mostly smooth. Add remaining ingredients (except topping ingredients and mix until combined.
- Spoon sweet potatoes into the casserole dish and use the back of a wooden spoon or mixing spatula to smooth out. Sprinkle marshmallows over top of mashed sweet potatoes.
- Add butter to a medium sized microwave safe bowl. Microwave on full power to melt the butter. Add remaining topping ingredients to the bowl, and use a fork to combine. Sprinkle over the top of casserole.
- Place the casserole in the preheated oven and bake for 20-25 minutes, or until the streusel is crisp and marshmallows are golden brown.
- Serve while warm, and enjoy!
Prepare the mashed sweet potatoes the day before and place them in your baking dish. Cover the dish with plastic wrap and refrigerate overnight. Bring it to room temperature the day of, add the marshmallows and streusel topping, and bake per recipe instructions.
All nutritional information is based on third party calculations and is only an estimate. Each recipe’s nutritional value will vary depending on the ingredients used, measuring methods, and portion sizes.
Originally published November 2013, updated and republished November 2022.
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