Sweet Potato Cupcakes with Toasted Marshmallow Frosting

Last Updated on November 10, 2022 by Jennifer Pallian BSc, RD

This moist Sweet Potato Cupcake recipe with fluffy marshmallow frosting is heavenly. My 2 pro secrets to moist cupcakes ensure they’re always super soft and tender.

You’ve gotta make these soft, fluffy sweet potato cupcakes with warm spices and toasted marshmallow frosting. They are a delicious fall treat made with sweet potato puree, nutmeg, ginger and cinnamon. With the fluffy topping, they’re like a sweet potato casserole in dessert form. I love this casual departure from the typical pumpkin desserts that are everywhere.

Start with canned sweet potato puree, or by roasting sweet potato from scratch.

The extra moisture in the sweet potato helps keep these cupcakes super tender and irresistible.

A sweet potato cupcake with a bite taken out.

Buy sweet potatoes, not yams

Be sure to buy orange sweet potatoes, not true yams (which are either brown or purple on the outside and white and starchy on the inside).

I say “true yams” because in North America we often refer to sweet potatoes as yams (yam fries, anyone?). You want the sweet potatoes typically used in American cooking, which are brownish-orange on the outside and orange on the inside.

The sweet potatoes you need for this recipe look like the ones in the photo below.

Ingredients for sweet potato cupcakes measure out on the counter.

How can I make my cupcakes moist?

To make sure your cupcakes don’t dry out, you’ve gotta use these pro secrets to moist cupcakes:

  • Weigh your flour to ensure moist cupcakes every time. A bit too much flour added by inaccurately measuring by volume can make ANY cupcake recipe dense and dry. 
  • If you do not have a kitchen scale, fluff your flour in the bag, then lightly spoon it into the measuring cup and level it off.
  • Check for doneness using a thermometer, not a toothpick. This ensures the cupcakes come out of the oven as soon as they are finished baking. Over-baking is another reason why cupcakes turn out dry.
  • Don’t over-mix the batter once the liquids are added. The more you mix, the more likely your cupcakes will turn out dense and not fluffy. The goal is to just combine the ingredients. Don’t use an electric mixer, just a large mixing bowl and a big ol’ silicone spatula.
  • Use oil instead of butter. Oil is fluid at room temperature, while butter firms back up to solid. This difference does impact the texture of the final cupcake, with an oil-based cupcake being more moist.

How to make marshmallow frosting

There are a few different methods to make a 7-minute frosting like this.

  • My favourite, most successful way is whipping the frosting fully over the boiling water bath until it is done.
  • The continuous heat ensures the sugar stays liquid for the entire time it takes for the whites to whip up.
  • It is key to use a very small amount of water in the saucepan under the bowl. An inch, no more.
  • The water should not come close to touching the bottom of the vessel with the sugar, or the sugar may crystallize.
  • Finally, cream of tartar is absolutely non-negotiable. Buy it. Only use it twice a year. Don’t regret it. It makes for the most beautiful, strong peaks and swirls that hold forever and ever.

Decorating the cupcakes

  • If you don’t have a kitchen torch you can toast the frosted cupcakes by placing them on a baking sheet and placing them under the broiler very briefly (and watching VERY carefully).
  • You may frost the cupcakes with whipped cream and dust them with ground cinnamon for a super simple frosting option.
  • Cream cheese frosting like the one used for these Spiced Parsnip Cupcakes is another great substitute.

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Sweet Potato Cupcakes with Toasted Marshmallow Frosting

Prep Time 20 mins
Cook Time 20 mins
Servings 12 cupcakes
Dessert
American

Ingredients
 
 

For sweet potato cupcakes:

  • 1 cup mashed sweet potato about 2 medium sweet potatoes or one large
  • ¾ cup packed brown sugar
  • cup vegetable oil like avocado oil
  • 2 large eggs
  • 1 tbsp pure vanilla extract
  • 1 cup all-purpose flour preferably weigh the flour 1 cup = 4.5 oz
  • 2 tsp ground cinnamon
  • 1 tsp ground ginger
  • ¼ tsp ground nutmeg
  • 1 ½ tsp baking powder
  • ½ tsp kosher salt

For marshmallow frosting:

  • 4 large egg whites room temperature
  • 1 ⅓ cup granulated sugar
  • ½ tsp cream of tartar
  • 1 tsp pure vanilla extract

Instructions
 

To make the sweet potato mash: 

  • To start, prick your sweet potato all over with a fork. Wrap in foil and roast at 400ºF until tender (45-60 minutes) OR peel, cut in cubes, and simmer on low until tender. When cool enough to handle, scoop out the flesh and mash with a fork.

To make the cupcakes:

  • Preheat oven (or reduce temperature) to 350ºF. Line a standard 12-cup muffin tin with paper liners.
  • Add sweet potato to a medium bowl and whisk in brown sugar, oil, eggs and vanilla extract to fully combine.
  • In a second large bowl, whisk together the flour, spices, baking powder, and salt. Add the sweet potato mixture and stir with a large spatula until just combined (don't overmix).
  • Divide batter among prepared muffin cups by filling each cup about half full. (If there's extra batter, go back and top them each up a little spoonful at a time to make them even).
  • Bake for 18-22 minutes, rotating pan once halfway through, until internal temperature reaches 190ºF. Cool on wire rack.

To make frosting:

  • Bring 1" of water to a strong simmer in a small saucepan. Combine egg whites, sugar and cream of tartar in a large heat-proof bowl set over top (or in a double boiler). Make sure your bowl does not touch the water.
  • With burner heat on low, beat with hand mixer until stiff, very glossy peaks form, about 7 minutes. Remove bowl from heat and beat in vanilla extract.
  • Pipe or spread frosting onto cupcakes (unlike with other frostings, they don't have to be completely cooled), then carefully toast with a kitchen torch or place frosted cupcakes on a baking sheet broil for 1-1 1/2 minutes (watching very closely).

Video

Notes

  • Be sure to buy orange sweet potatoes, not yams (which are either brown or purple on the outside and white and starchy on the inside). See photo example in blog post.
  • Sweet potatoes lose moisture (and thus weight) when water escapes as steam while they cook. To ensure moist cupcakes, minimize the steam loss by wrapping the sweet potatoes tightly in foil before roasting, or cook them cubed in simmering water. The weight of raw sweet potato to yield 1 cup mashed is therefore an estimate, as the moisture loss varies.
  • I highly, highly recommend you weigh your flour to ensure moist cupcakes every time. A bit too much flour added by inaccurately measuring by volume can make ANY cupcake recipe dense and dry. 
  • If you do not have a kitchen scale, make sure you fluff your flour in the bag, then lightly spoon it into the measuring cup and level it off.
  • Check for doneness using a thermometer, not a toothpick. This ensures the cupcakes come out of the oven as soon as they are finished baking. Over-baking is another reason why cupcakes turn out dry.
  • Don’t overmix the batter once the liquids are added. The more you mix, the tougher cupcakes become. The goal is to just combine.
FROSTING TIPS
  • If you have a gas stove, make sure to keep the flame low. You don’t want the bottom of the bowl to touch the simmering water OR the direct heat of the flame.
  • Dampen a paper towel with vinegar and wipe down bowl and beaters before you start. Rinse completely with water and then dry with a clean dish towel. This ensures no oil residue is leftover from previous baking. Any trace of fat can stop egg whites from whipping up.
  • If you don’t have a kitchen torch you can toast the frosted cupcakes by placing them on a baking sheet and placing them under the broiler very briefly (and watching VERY carefully).
  • You may frost the cupcakes with whipped cream and dust them with ground cinnamon for a super simple frosting option.

Nutrition

Calories: 175kcalCarbohydrates: 34gProtein: 6gFat: 2gSaturated Fat: 0.4gPolyunsaturated Fat: 1gMonounsaturated Fat: 1gTrans Fat: 0.003gCholesterol: 31mgSodium: 228mgPotassium: 159mgFiber: 2gSugar: 23gVitamin A: 2714IUVitamin C: 0.5mgCalcium: 58mgIron: 1mg
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Susan
Susan
18 days ago

Could we have a more accurate measurement for the sweet potatoe.

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