Sweet Potato Layer Cake with Spiced Pecan Buttercream

Total Time:
4 hr 40 min
1 hr
2 hr 10 min
1 hr 30 min

10 to 12 servings

  • Spiced Pecans:
  • 2 1/2 cups pecan halves
  • 1/3 cup packed dark brown sugar
  • 2 tablespoons ground cinnamon
  • 2 teaspoons ground nutmeg
  • 5 tablespoons unsalted butter, melted
  • 2 tablespoons dark rum
  • Cake Layers:
  • 2 pounds sweet potatoes
  • 4 large eggs
  • 2 cups sugar
  • 1 cup canola oil
  • 2 cups cake flour
  • 2 teaspoons baking powder
  • 1 teaspoon salt
  • 1 tablespoon ground cinnamon
  • 1 teaspoon ground nutmeg
  • 1 teaspoon ground ginger
  • 2 teaspoons pure vanilla extract
  • 3 tablespoons rum
  • 1 1/4 cups chopped Spiced Pecans
  • Spiced Pecan Buttercream:
  • 6 large egg yolks
  • 3/4 cup sugar
  • 1/2 cup light corn syrup
  • 1 pound unsalted butter, room temperature
  • 1 tablespoon vanilla extract
  • 1/8 teaspoon salt
  • 3/4 cup Spiced Pecans
  • Assembly:
  • 1/2 cup chopped Spiced Pecans
  • Make Spiced Pecans: Preheat the oven to 350 degrees F.

  • Place the pecans in a single layer on a baking sheet and toast them for 10 minutes, until fragrant. Meanwhile, combine the brown sugar, cinnamon, and nutmeg in a medium bowl, using your fingers to mix everything thoroughly. Stir in the melted butter to make a paste. Add the toasted pecans to the mixture and stir to coat, then spread them evenly on the baking sheet and return to the oven for 8 minutes. Remove from the oven, drizzle over the rum, and bake for 8 more minutes, stirring once. Remove from the oven, cool completely and leave the oven on. When cool, chop the pecans into medium-fine pieces, some larger than others, and set aside.

  • Meanwhile, pierce the sweet potatoes with a fork. Microwave on high until very tender, about 8 minutes per side. Cool, peel, and mash the sweet potatoes with a potato masher or fork.

  • Lower oven temperature to 325 degrees F. Spray 2 (8-inch) round cake pans with nonstick baking spray and set aside. In the bowl of an electric mixer fitted with the paddle attachment, beat the eggs and sugar together on medium speed until light and fluffy, 4 minutes. Add the canola oil; beat on medium until combined. Add the mashed sweet potatoes and mix until combined. Sift together cake flour, baking powder, salt, cinnamon, nutmeg, and ginger and then mix the dry ingredients into the sweet potato mixture. Mix in vanilla and rum. Fold in 1 1/4 cups of the chopped Spiced Pecans by hand. Evenly distribute cake batter into the prepared pans, and transfer to the oven. Bake until a toothpick inserted into the center comes out clean, 40 to 45 minutes. Let pans cool on a wire rack 10 minutes. Invert cakes onto rack; cool completely.

  • Make the buttercream while the cake is baking: Beat the egg yolks in the clean bowl of an electric mixer fitted with the paddle attachment on medium-high until very thick, about 5 minutes. Combine the sugar with the syrup in a small saucepan, and set over medium-high heat, stirring constantly until the mixture comes to a full boil. Immediately scrape the mixture into a heatproof 1-cup glass measure. With the mixer on high speed, pour a few tablespoons of the sugar mixture into the yolks and beat for a few seconds. Repeat until all of the syrup has been added. Beat until the bowl has cooled to room temperature. On medium speed, add the butter, 2 tablespoons at a time, beating well after each addition. The frosting will begin to come together after all of the butter has been incorporated (it will look curdled first, but be patient and it will come together beautifully!). Scrape the bowl and beat in the vanilla and salt. Mix in 3/4 cup chopped Spiced Pecans.

  • Cut each cooled cake layer in half horizontally, creating 4 layers. Set 1 layer, cut side up, on a cake round or cake plate and spread a thin layer of frosting on the surface. Stack next layer on top, and frost. Repeat frosting-and-stacking process until each layer is frosted. Spread remaining frosting on sides and top of cake. Arrange remaining Spiced Pecans decoratively on top of cake. Chill for 1 hour or serve immediately if you can't wait!

  • A viewer, who may not be a professional cook, provided this recipe. The Food Network Kitchens chefs have not tested this recipe and therefore, we cannot make representation as to the results.

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4.4 7
This is probably the best cake I have ever tasted. I used a cream cheese frosting (adding the spiced pecans instead of the one in this recipe and it was delicious. I get lots of requests to make this, but you have to plan ahead because it takes a bit of time. item not reviewed by moderator and published
Loved watching URS last year, so I decided to try a few recipes before the new season starts. Made this for a luncheon yesterday, and every last crumb was gobbled up. I was able to get 16 thin servings, because you don't need much (lots of butter). I'm glad that I gave myself some extra time because there are several steps, but as another reviewer commented, it was WORTH IT! The cake was very moist, and the butter cream was silky. It was very buttery, but the spiced nuts mixed in gave it a delicios and unique taste. Oh, and the nuts are good on their own too! This probably won't become my go-to every day cake, but it might become my special occasion cake. item not reviewed by moderator and published
I thought recipes for the Ultimate Recipe Showdown were supposed to be original. This is very much like a recipe I have from a magazine several years ago. The frosting is different but the cake is almost exact except for the addition of Run. item not reviewed by moderator and published
The cake layers themselves were exquisite: moist, full of flavor, and the perfect consistency. The spiced pecans were also phenomenal (although mine turned fragrant at seven or eight minutes instead of ten). The frosting, however, just didn't do it for me. A *pound* of butter?!?! Yikes! If you divide this cake into ten servings as the recipe suggests, that's a whopping 3.2 tablespoons of butter per slice. The frosting just tastes like ... butter. I would have much preferred a more traditional less-butter dressed-up buttercream or, even better, a cream cheese frosting. item not reviewed by moderator and published
WOW! All we can say is WORTH THE PREP/COOK TIME! Tastes and looks SO GREAT that my boyfriend and I took pictures of the finished product - after week ate a piece of course... item not reviewed by moderator and published
One of the best cakes I have ever had! It was well worth the time it took to make. I have never made a frosting like this one, but it came out beautifully and was sinful! 4 stars!! item not reviewed by moderator and published
I made this today with my daughter after watching the show because we love sweet potatos. The cake is nicely flavored with the spices and moist, but ohhh that buttercream with the spiced nuts was so delicious. We kept sticking our fingers in the bowl. There were several steps in the process, but I would make it again for a holiday or special occasion. item not reviewed by moderator and published
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