Sweet Potato Cake with Marshmallow Frosting
Transform a traditional Thanksgiving side dish into the perfect dessert with this Sweet Potato Cake with Marshmallow Frosting.
- Prep time
- 2 hr
- Cook time
- 40 min
- Yield
- 12 servings
- Difficulty
- HARD
Ingredients
- 2+1/2 cup all-purpose flour
- 2+1/4 tsp baking powder
- 1 tsp ground cinnamon
- 1/4 tsp ground nutmeg
- 3/4 tsp salt
- 6 tbsp unsalted butter (melted, cooled)
- 6 tbsp vegetable oil
- 1 cup granulated sugar
- 1 cup light-brown sugar (packed)
- 1+1/2 cup sweet potato puree
- 3 large eggs (room temperature)
- 1 tsp vanilla extract
- 2/3 cup water
- 1+1/2 cup granulated sugar
- 1+1/2 cup light corn syrup
- 6 large egg whites (room temperature)
- 1 tsp cream of tartar
- 2 tsp vanilla extract
Instructions
- 1
Preheat oven to 350F and grease & flour two 8" cake pans.
- 2
In a medium bowl, whisk together flour, cinnamon, nutmeg, baking powder, and salt.
- 3
In a large bowl, whisk together sugars, melted butter, oil, sweet potato, and eggs.
- 4
Add dry to wet and mix until just combined.
- 5
Divide batter evenly between prepared pans and bake until a toothpick inserted into the center comes out mostly clean (approx. 35-40 mins).
- 6
Cool in pans on wire rack for 10mins, then turn out onto wire racks to cool completely.
- 7
Place water, sugar, and corn syrup in a medium saucepan. Stir to combine.
- 8
Insert a candy thermometer into the pot and heat over medium-high. Do not stir from this point on as crystals will form.
- 9
Ensure mixer bowl and whisk are completely grease free.* Place egg whites and cream of tartar in the bowl of a stand mixer.
- 10
When the sugar syrup reaches about 225°F, start whipping the egg whites to soft peaks.
- 11
When the whites are ready, the sugar syrup should be at 240°F. Remove from the heat, turn mixer to medium and very slowly and carefully pour the sugar syrup into the whites in a thin, steady stream.**
- 12
Once all of the syrup is in, set mixer to medium/high and continue whipping. The whites will deflate at first, but they will thicken and fluff up.
- 13
Continue to whip for 7-8 minutes, or until the mixture is thick and glossy. Add in vanilla and whip until the fluff has cooled.
- 14
Place one layer of cake onto a serving plate or cake stand. Top with 1 cup marshmallow fluff. Spread evenly. It will be thick and sticky.
- 15
Place remaining layer on top and do a thin coat of marshmallow all around the cake, just to hide any dark bits of cake.
- 16
Using a 1M piping tip. Pipe rosettes along the sides and top of the cake. Torch with a kitchen torch if desired.***