Recipe: Sweet Potato Cake with Marshmallow Buttercream


Years back, I attended a baking retreat hosted by Martha White with my buddy Brandie from The Country Cook. While there, we were tasked with creating a recipe using Martha White’s sweet potato muffin mix. We created this amazing Sweet Potato Cake with Marshmallow Buttercream Frosting. Sadly, though, it’s become increasingly difficult to find that muffin mix and I think it might actually be discontinued.

A carrot cake recipe with an amazing sweet potato twist. (Stacey Little/Southern Bite)

So when I was thinking about fall recipes and things I might be able to do with sweet potatoes, I thought I might give that old recipe a bit of a makeover and make it a bit more timeless. This new version of Sweet Potato Cake with Marshmallow Buttercream was born and, boy, is it an improvement.

In thinking about this, I decided that something akin to a carrot cake would make a great vehicle for some sweet potatoes. So I took Heather’s Great Aunt Frankie’s ridiculously amazing recipe for carrot cake and I gave it a sweet potato twist.

This perfectly dense, amazingly moist cake isn’t crazy sweet, so the marshmallow buttercream is the perfect sweet topping. I mean, sweet potatoes and marshmallows go together perfectly, right?

It has the perfect amount of sweet potato flavor without being overwhelming.

A few things to keep in mind:

You’ll need about 3 cups of shredded (or grated) sweet potatoes for this recipe. I just used a box grater to shred mine, but you can use a food processor as well. It took about 1 1/2 medium sweet potatoes to yield 3 cups. I like to bake this cake in a light-colored metal pan, but a ceramic or glass baking dish will work as well. Just keep in mind that using a different type of baking vessel may change the cook time. Dark-colored metal baking pans can often burn the outside of baked goods like this that require a lengthy time in the oven, so I might reduce the heat about 25 degrees to help prevent that from happening.

Yes, pecans can be a little pricey, but they’re worth it. Be sure to buy chopped pecans for this recipe. They’re cheaper to buy in pieces and it saves you the step of having to chop them. You can also use walnuts, if you wish.

I suppose that one really large potato might give you enough also.

If you love sweet potatoes and the dense texture and warm spice flavor of carrot cake, you’re going to love this. It might just be my new favorite dessert. Pumpkin spice ain’t got nothing on this one. Y’all enjoy.

Top with chopped pecans or walnuts. (Stacey Little/Southern Bite)

Sweet Potato Cake with Marshmallow Buttercream

Prep time: 30 minutes

Cook time: 50 minutes

Serves: 12


  • 2 1/2 cups self-rising flour
  • 1 teaspoon baking soda
  • 1 1/2 teaspoons ground cinnamon
  • 2 cups sugar
  • 1 cup vegetable oil
  • 4 large eggs
  • 3 cups grated raw sweet potatoes (1 to 2 medium sweet potatoes)
  • 1 1/2 cups chopped pecans

Buttercream Frosting

  • 1 cup unsalted butter, room temperature
  • 2 (7-ounce) containers marshmallow cream
  • 2 cups powdered sugar
  • 1 pinch salt


  1. Preheat the oven to 350 degrees and lightly spray a 9-by-13-inch baking pan with nonstick cooking spray.
  2. In a large bowl, whisk together the flour, baking soda and cinnamon. Set aside.
  3. Use an electric mixer to beat together the sugar and oil until well combined.
  4. Add the eggs, one at a time, beating well after each addition.
  5. Add the flour mixture, all at once, and mix on low speed until well combined.
  6. Scrape down the sides of the bowl and mix again to ensure everything is combined.
  7. Fold in the sweet potatoes and pecans, reserving a few pecans to sprinkle on the top at the end.
  8. Pour the batter into the prepared pan. Bake for 50 to 60 minutes, or until a toothpick inserted in the center of the cake comes out clean.
  9. Cool completely.

For the frosting:

  1. Use an electric mixer to beat the butter until smooth.
  2. Add the marshmallow cream and mix until combined.
  3. Add the powdered sugar and a pinch of salt and mix until combined.
  4. Spread the buttercream on the cooled cake. Store the cake in the refrigerator.

This recipe originally appeared on For more great recipes, visit the website or check out ”The Southern Bite Cookbook.”

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