Delicious Fall-Inspired Sweet Potato Cake

Sweet Potato Cake – sweet potato cake layers with toasted marshmallow filling, toasted pecan crunch and pecan buttercream.

Sweet Potato Cake on a cake stand.

Sweet Potato Casserole

While it’s easy for me to jump from Halloween to Christmas without skipping a beat, I really do love Thanksgiving. Thanksgiving food is some of my favorite: homemade rolls, stuffing, and sweet potato casserole. (Gimme all the carbs!).

A good sweet potato casserole is probably my most favorite dish on Turkey Day. I’ve tried a variety over the years, but my go-to version is simply made up of mashed sweet potatoes, brown sugar and toasted marshmallows and pecans.

Thinking about all those amazing flavors and textures, it only seemed fitting to throw them into a cake.

Pecan Butter Buttercream on a cake.

Sweet Potato Cake

Mastering a delicious sweet potato cake was priority number one for me. Sweet potatoes help give the cake moisture and flavor. It’s just a matter of getting the right amount.

Last year I created a butternut squash cake that was to-die-for. I roasted the butternut squash to get it nice and soft and then used about three cups of mashed squash in the cake batter. Once you add all the sugar and other ingredients, you don’t have an overwhelming vegetable flavor – just enough to hint to the butternut squash, but not so much that you think you’re eating it as a dinner side 😉

Cake on a cake stand with cake slices around it.

With a good foundation already in hand, I decided to use the butternut squash cake as the base for this cake.

I first roasted my sweet potatoes to get them nice and soft for mashing. Once cooked, I mashed the sweet potatoes and measured about three cups (about 600 grams). It took three very large sweet potatoes to get this amount.

Because the sweet potatoes don’t have quite the same water content the butternut squash does, you’ll notice the batter for the sweet potato cake is much thicker than the butternut squash batter. Both bake up super moist!

Inside view of a cake.

Are you dying over this color?! I love how brightly colored this cake turned out just from the natural color of the sweet potatoes. It screams “Thanksgiving” to me!

Toasted Marshmallow Filling

The marshmallow filling for this was a no-brainer. I am obsessed with the toasted marshmallow filling in my Ultimate S’mores Cake. It’s inspired by a Sweetapolita recipe. I changed up the quantities a bit to include more toasted marshmallow. That idea was genius, Rosie!

Slice of cake on a plate.

Pecan Buttercream

And you know me, I love a good crunch in my cakes. Similar to my Butternut Squash Cake, I added toasted pecans between layers. I also added the toasted pecans to the buttercream, in the form of a nut butter. You guys! I think you’ll go nuts over this one (pun totally intended)!

Truly, the combination of flavors and textures in this one is a homerun, if you ask me! I hope to see it on your Thanksgiving table or next gathering. I have no doubt it will be a huge hit!

Allergy note:

I know many of you or your loved ones have nut allergies you have to be mindful of when baking. I’d hate for you to miss out on this cake because of the pecans, so here are some alternative buttercream flavors I think would be awesome with this cake:


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Sweet Potato Cake - the perfect cake for your Thanksgiving table, inspired by my favorite sweet potato casserole #cakebycourtney #sweetpotatocake

Sweet Potato Cake

Sweet potato cake layers with toasted marshmallow filling, toasted candied pecans and pecan buttercream.
4.9 from 38 votes
Prep Time 2 hrs
Cook Time 26 mins
Course Dessert
Cuisine Cake
Servings 18 people


For the Cake

  • 3 cups (600 g) mashed sweet potatoes about three large sweet potatoes
  • 1 1/2 cup (300 g) granulated sugar
  • 5 large or extra large eggs room temperature
  • 1 cup (218 g) vegetable oil
  • 3 cups (345 g) cake flour
  • 1 tbsp (8 g) cinnamon
  • 2 tsp (8 g) baking powder
  • 1 tsp (5.6 g) salt
  • 1 tsp (3 g) nutmeg
  • ½ tsp (1.5 g) ground ginger
  • 2 tsp (8.4 g) vanilla extract

Toasted Marshmallow Filling

  • 24 large marshmallows
  • 1 cup (226 g) unsalted butter room temperature
  • 1 1/2 cups (187.5 g) powdered sugar measured and then sifted
  • 1/2 jar marshmallow fluff about 100 grams
  • 1 tsp (4.2 g) vanilla extract

Toasted Pecans and Pecan Butter

  • 2 cups (300 g) chopped pecans
  • ½ cup (100 g) granulated sugar
  • 1 tbsp (13.6 g) olive oil

Pecan Buttercream

  • 6 cups (750 g) powdered sugar measured and then sifted
  • 2 cups (452 g) unsalted butter slightly cold
  • pecan butter recipe above
  • 3 tbsp (43.3 g) heavy cream
  • *This buttercream recipe makes enough to fill and cover your cake. If you want to add additional piping, you’ll want to make an extra ½ batch.


For the Cake

  • Preheat your oven to 350 degrees F. Spray three 8-inch or four 6-inch round cake pans with non-stick spray, line with parchment and spray again. Set aside.
  • In a medium bowl, combine the cake flour, cinnamon, baking powder, salt, nutmeg, and ground ginger. Set aside.
  • In the bowl of an electric mixer fitted with the paddle attachment, beat the sugar and eggs together on medium-high speed until light and fluffy, about five minutes. Add the oil and beat on medium until combined. Add the cooled sweet potatoes and mix until combined. Add the vanilla.
  • With the mixer on low, gradually add the dry ingredients. Stir until just combined. 
  • Evenly distribute the batter into the prepared pans (about 20 ounces of batter in each of the three 8-inch round pans or 15 ounces of batter in each 6-inch pan). Bake for 30 to 35 minutes, or until a toothpick inserted in the center of the cakes comes out mostly clean.
  • Let pans cool on wire racks for 10 minutes before inverting cakes onto racks to cool completely.

For the Marshmallow Filling

  • Place the marshmallows on a cookie sheet lined with parchment paper and sprayed with nonstick cooking spray. Place on the middle rack of the oven, and broil the marshmallows until golden brown on top, about 30-60 seconds. Keep your eye on them!
  • Remove the pan from the oven and gently turn the marshmallows over and broil them again until they are golden brown on the other side.
  • In the bowl of a stand mixer fitted with the paddle attachment, combine the butter and powdered sugar and beat on low until blended. Add the vanilla and mix on medium speed for about three minutes.
  • With the mixer on low speed, add the marshmallow cream and (cooled) toasted marshmallows, and mix for about one minute. 

Toasted Pecans

  • Over medium heat, toast the 2 cups of pecans in the olive oil, stirring frequently. Once toasted, remove one cup of the pecans and cool them on parchment paper.
  • While the 1 cup of pecans is cooling, add the sugar to the remaining pecans and stir until the sugar is dissolved and is coating the pecans. Pour the sugared pecans over other parchment to cool and use for the filling.

For the Pecan Buttercream

  • In a food processor, combine the one cup of (non-sugared) toasted pecans with 1 tablespoon olive oil. Pulse until you've created a smooth nut butter.
  • In the bowl of an electric mixer, fitted with the paddle attachment, beat the butter for about 2 minutes on medium-high speed. This helps to soften the butter without the butter getting too warm by sitting on the counter half the day.
  • Add your homemade pecan butter. Mix on medium-high speed until well blended, making sure to scrape down the sides and bottom of your bowl.
  • With the mixer on low speed, gradually add the powdered sugar, followed by the cream. Turn the mixer to medium-high and beat the buttercream for about 3 to 5 minutes.
  • Before spreading on your cake, spend a couple minutes mixing the buttercream by hand with a wooden spoon to push out the air pockets. 


  • Place your first cake layer, top side up on a cake board or cake plate. Spread about ¾ cup of the marshmallow filling over the cake, followed by a generous sprinkle of the toasted pecans.
  • Place the second cake layer on top of the fillings and layer with another ¾ cup marshmallow filling and more pecans.
  • Cover the entire cake with a thin coat of the pecan buttercream. This is your crumb coat. It's not meant to be beautiful, it's meant to be functional – so don't spend a lot of time on this or use too much frosting. You'll freeze the crumb coat for 10 to 15 minutes to lock in the crumbs.
  • After the crumb coat is set, continue frosting the cake with the remaining buttercream.
Tried this recipe?Let us know how it was!

Courtney Rich

I’m a self-taught baker, obsessed with cake.

I long ago ditched box mixes in pursuit of melt-in-your-mouth, to-die-for flavor combinations, fillings and textures. I believe cake must be decadent, life-changing and worthy of celebration! And I believe anyone should be able to bake that kind of cake – and I’m here to teach you just that!

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Recipe Rating


  1. I can’t wait to try this for Thanksgiving! It looks ammaaazing!

    After reading over the recipe I wonder if the cake would get fibrous strings from the sweet potatoes? As a preventative measure I would first use my kitchen aid or a handheld mixer to whip the massed sweet potatoes, when you do this the fibrous strings will get caught in the mixer beaters so you can clean them and do it once or twice more to make sure no more strings are left. I don’t see any strings in the picture but not all sweet potatoes are alike.

    I’ll be back with a review for this amazing cake!

  2. Can you just confirm for me…is it 3 cups of sweet potatoes or 3 cups of yam? Sometimes these are used interchangeably so I want to make sure I’m using the right one.

  3. So I made this cake, and it turned out like a brick. I’ve never had a recipe fail from you yet! I’m wondering if this is because there was no baking soda in the recipe? I’m going to try and remake it in my 6inch pans and see what happens.

    1. There’s baking powder which should make it rise nicely. It’s definitely a moist, tender cake. How old is your baking powder?

  4. So excited to make this cake next week. But I had a question. Would using canned sweet potatoes add to much liquid or do you think I might be able to use them if I strained them before use? Just trying to save a little extra time in prep. Thanks so much Courtney!

  5. The metric conversion of the recipe calls for 500g of sweet potatoes. The text of the blog posts says “measured about three cups (about 600 grams).” Looking around online it looks like 600 is probably right?




  7. Hello Courtney! Please disregard my question about the olive oil! Duh! I hadn’t gotten far enough along in the recipe to see when the olive oil is used. And it makes sense that it would be large marshmallows. Because we’re traveling – I actually made the cake and frosting on Monday. Froze the cake layers. Will make the marshmallow filling once we reach our destination, then assemble!

    I just love your passion for cakes and your beautiful blog! Happy Thanksgiving!

  8. I can’t seem to get this baking-with-vegetables thing down. The flavor of this cake was fantastic, but the texture came out dense and gummy. The same thing happened when I made the Butternut Squash Gingersnap cake. My baking powder is new and my oven temp is not off, so I’m not sure what else is going wrong :/

  9. 4 stars
    I have made this cake 3X’s now and I have to agree that the recipe as written does not yield a good rise. The first time I made it I was worried that the cake didn’t include any milk or baking soda so I followed the recipe as written plus added 1/2 cup of room temp. buttermilk and 1/2 teaspoon of baking soda, but the cake came out dense. I figured I would try it again but without making any changes to the recipe, the cake still came out dense (This time I 1/3rd all ingredients because I only needed 1 more layer to make up for the flat layers from the first attempt). Also, I bought fresh baking soda and baking powder so this was not the issue and all ingredients were room temp. The final try I added 1 full cup of room temp buttermilk plus 2 teaspoons of baking soda and used a total of 4 room temp eggs INSTEAD of 5. PERFECT. The cake had a great rise and didn’t fall flat and dense. I will say the first time making this cake (3 layers from the first try and 1 layer following the recipe) still yielded an amazing cake. The cake as written is still being talked about in my office as being sooo goood. So that being said if you follow the recipe to a T it will still come out tasting great but it MAY NOT rise like you’d hope and see in the video on the site. If you want to guarantee this cake will rise add 1 cup of room temperature buttermilk and 2 TEASPOONS of baking soda and reduce the egg count to 4 room temp eggs.

    One thing about the candied pecans. I had trouble with my pecans ever absorbing the sugar without any liquid so when I make the filling again I will change up the preparation of the candied pecans. Maybe toasting the pecans then melting a tablespoon of butter and adding the sugar (I would then add cinnamon for an extra touch) and let it melt together then I would add the pecans back to the pan this should yield a better coat on the pecans. My pecans came out tasty following the recipe but they were mostly sugared pecans versus candied pecans.

    Also just a side note I wonder maybe the difference in bakers results is in the prep of the sweet potatoes. I wonder if she used boiled, baked, or steamed sweet potatoes. That might be the issue here. If the sweet potatoes are boiled you will get sweet potatoes that are more wet because of the absorption of the water while boiling. If you bake them of course you’d get a “dryer” and sweeter sweet potato. Just an FYI I used baked sweet potatoes for each attempt for the depth of flavor.

    In all, this cake is still amazing as written. I would make it as written if say I ran out of buttermilk and it will still taste great.

  10. Just baked these cake layers and coming out of the oven they were quite tall but as they cooled shrunk to 5/8th-inch. Is that where they should be or did I do something wrong? Thanks.

  11. 5 stars
    I made this cake for Thanksgiving/husband’s birthday and it was delicious!! The fact that the pecan buttercream even made it on the cake is a miracle. The pecan buttercream has got to be the best buttercream I have ever had. I look forward to making this cake again!!

  12. 5 stars
    I LOVE this cake! Great recipe.
    However it is missing a very important step-it needs a rim of frosting around the edge to hold in the marshmallow filling. For experienced cakers, no issue. For us novices, well, it was a learning experience. Just would love to save others from my “flowing out the sides “ experience. 💖💖💖

  13. 2 stars
    The flavor was nice but this came out so dense. My kids said it’s like think pumpkin pie. Maybe too many eggs or the cake flour which has cornstarch in it? So disappointed and will probably not make this again.

  14. 5 stars
    I love sweet potato since I first tasted one call that came with a piece of grilled salmon. Pure heaven.
    Aways have sweet potato pie at Thanksgiving. The pumpkin pie is the one eaten.
    I do believe this cake will be my sweet potato winner. This makes me want to cook it today.
    Thank You for making this recipe.