This richly spiced sweet potato cake evokes cozy autumn flavors. A quick marshmallow buttercream that comes together in minutes and a homemade caramel drizzle make this cake indulgent and memorable.
Sweet potatoes often get a bad rap from childhood memories, but when baked into desserts they become comforting and delicious.
Whether mashed into doughnuts, churned into ice cream, or folded into cinnamon rolls, sweet potato adds a unique, moist texture and warm flavor.
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Ingredients
Below are helpful notes and the reasons this recipe works. A full ingredient list and measurements follow in the recipe card.
- Sweet potato: Canned sweet potato puree is convenient and reliable. If unavailable, roast two whole sweet potatoes at 350°F until tender, peel, and puree until smooth.
- Eggs: Room-temperature eggs mix into the batter more evenly and help produce a consistent crumb.
- Milk: Whole milk adds richness, but 2% or 1% also work. Avoid skim for best texture.
- Unsalted butter: Adds flavor and moisture to the cake and forms the base of the frosting.
- Cinnamon and ginger: These warm spices give the cake a cozy, pumpkin-spice-like profile.
- Marshmallow fluff: Provides the signature marshmallow taste and light texture for the buttercream.
- Powdered sugar: Sweetens and smooths the frosting for a silky finish.
Working ahead
The cake layers can be wrapped individually in plastic and refrigerated for 3–5 days or frozen up to three months. If frozen, level or divide layers before frosting.
The frosting stores in an airtight container in the refrigerator for up to 7 days or frozen for up to three months. Bring to room temperature and re-whip briefly before using.
How to make sweet potato cake
First, prepare the cake batter.
Cream butter and sugar until light and fluffy, then beat in eggs one at a time. With the mixer on low, add the dry ingredients in two portions, alternating with the wet ingredients added in one portion. Bake the layers for 25–30 minutes or until a toothpick comes out clean.
Second, make the caramel.
Melt granulated sugar over medium-high heat, stirring constantly until smooth. Stir in the butter until melted, then add the heavy cream and let it bubble for about a minute. Remove from heat and cool.
Third, whip the frosting.
Beat softened butter and marshmallow fluff until smooth. Add powdered sugar slowly on low, then increase speed and beat until silky and light.
Finally, assemble the cake.
Spread a thin layer of frosting on the first cake layer, stack the next layer, and repeat. Crumb coat the assembled cake and chill briefly to set.
After the crumb coat sets (about 15 minutes), finish frosting the top and sides smoothly.
Warm the caramel slightly so it pours easily, drizzle over the top, and garnish with fresh fruit, berries, or edible flowers that are safe for cakes.
Expert tips
- Measure your batter: For even layers, aim for about 12 oz of batter per 6″ pan when dividing between three pans.
- Chill the cake: A slightly chilled cake is easier to trim, fill, and frost cleanly.
- Eliminate air bubbles: If your frosting has many air pockets, run the mixer on low for 3–5 minutes to smooth them out.
- Smooth frosting technique: Use a rotating cake stand and a bench scraper. Scrape off excess frosting, then warm the scraper with hot water, wipe dry, and smooth the exterior for a polished finish.
- Caramel shortcut: Store-bought caramel can replace homemade—use about 1/3 to 1/2 cup for drizzling.
Storage
Uncut, this cake keeps at room temperature for 3–4 days if covered with a dome, bowl, or boxed. Once sliced, cover exposed areas with plastic wrap to prevent drying.
More fall treats
Fall baking is ideal for warming spices and hearty desserts. Below are a few seasonal favorites that pair well with this cake.
- Pecan Upside Down Cake
- Cranberry Apple Crisp
- Pumpkin Oatmeal Cookies with Browned Butter Icing
- Bourbon Butterscotch Cinnamon Rolls
Did you make this recipe? Please leave a star rating and share feedback in the comments — I update these posts based on reader notes.
Recipe
Sweet Potato Cake
4.6 from 11 reviews
This richly spiced sweet potato cake features a light marshmallow buttercream and a buttery caramel drizzle for an unforgettable fall dessert.
- Author: Claire Coffey
- Prep Time: 40 minutes
- Cook Time: 30 minutes
- Total Time: 1 hour 10 minutes
- Yield: 16 slices
- Category: Dessert
- Cuisine: American
Ingredients
Units
Scale
For the sweet potato cake:
- 3 eggs
- 1 ½ cup granulated sugar
- ½ cup unsalted butter
- 1 – 14oz can sweet potato puree
- ½ cup milk
- 1 tsp ground cinnamon
- ½ tsp ground ginger
- 2 tsp baking powder
- 1 tsp vanilla extract
- 1 ½ cup all purpose flour
For the marshmallow frosting:
- 4 sticks unsalted butter, softened
- 2 – 7.5oz containers marshmallow fluff
- 2 cups powdered sugar
For the caramel:
- 1 cup granulated sugar
- 6 tbsp butter, salted and cubed
- ½ cup heavy cream
Instructions
- Grease and line the bottom of three 6″ round cake pans.
- Cream the butter and sugar on medium until light and fluffy, about 2–3 minutes.
- Reduce mixer to low and beat in the eggs one at a time until just combined.
- Whisk dry ingredients (flour, baking powder, ginger, and cinnamon) together. In a separate bowl combine milk, sweet potato puree, and vanilla.
- With the mixer on low, add the dry ingredients in two increments, alternating with the wet ingredients. Mix until just combined.
- Divide batter evenly among prepared pans.
- Bake 25–30 minutes, or until a toothpick inserted in the center comes out clean.
- When pans are cool enough to handle, turn cakes out onto plastic wrap, seal, and chill in the refrigerator.
- For the caramel, melt granulated sugar in a small saucepan over medium-high heat, stirring constantly until smooth.
- Add cubed butter and stir until melted and combined.
- Pour in heavy cream, allow the mixture to bubble for a minute while stirring, then remove from heat and cool.
- In a stand mixer bowl, beat butter and marshmallow fluff until smooth.
- Slowly add powdered sugar on low until incorporated.
- Increase mixer speed and beat until the frosting is light and smooth.
- Assemble the cake by alternating layers of cake and thin layers of frosting. Apply a crumb coat and chill until set.
- Finish frosting the top and sides, then refrigerate about 15 minutes to firm.
- Warm the caramel briefly so it pours easily and drizzle it over the chilled cake.
- Garnish with fresh fruit such as figs, grapes, and blackberries.
Notes
- Make your own sweet potato puree: Roast two sweet potatoes at 350°F for 1–2 hours until tender, peel, and puree.
- Even layers: Aim for roughly 12 oz of batter per pan for balanced 6″ layers.
- Chill before finishing: Cooling the cake briefly makes trimming and frosting much easier.
- Remove frosting air bubbles: Beat the frosting on low for 3–5 minutes to smooth out air pockets.
- Smooth finish trick: Use a rotating cake stand and bench scraper, wiping the scraper in hot water between passes for a clean finish.
- Caramel shortcut: Ready-made caramel works as a substitute—use 1/3–1/2 cup.
- Storage: Uncut, the cake keeps at room temperature for 3–4 days; cover well. For cut cake, wrap exposed sections with plastic wrap to retain moisture.
Nutrition
- Serving Size: 1 slice
- Calories: 824
- Sugar: 34.3g
- Sodium: 533mg
- Fat: 61.6g
- Saturated Fat: 38.7g
- Carbohydrates: 68.3g
- Fiber: 1.1g
- Protein: 4g
- Cholesterol: 192mg
Update Notes: This recipe was originally published in 2015 and updated with new photos, directions, and tips in 2019.
I’ve learned that styling and decorating start during recipe development—thinking about how a cake will be finished helps produce better photos and a more polished final dessert.
The updated version of this cake leans toward an organic, Thanksgiving-style presentation rather than rigid, hard-edged decorations.
