Purple Sweet Potato Cake
Recipe type: Dessert
Serves: 1 3-layer 8-inch cake
For the Purple Sweet Potato Cake:
  • 2 ¾ cups all-purpose flour
  • 2 teaspoons baking powder
  • 1 teaspoon baking soda
  • ½ teaspoon fine salt
  • 1 ½ cups granulated sugar
  • 1 cup cooked mashed purple sweet potato, preferably Stokes Variety
  • Purple food gel
  • 1⁄3 cup canola oil
  • 2 large eggs, room temperature
  • 1 cup buttermilk, room temperature
  • ½ cup sour cream, room temperature
  • 2 teaspoons vanilla extract
For the Whipped Tofu Filling:
  • 1 ½ cups heavy cream
  • 1 teaspoon vanilla extract
  • 2 teaspoons granulated sugar
  • ½ cup (1 stick, 4 ounces) unsalted butter, room temperature
  • 2 cups powdered sugar
  • ⅛ teaspoon fine salt
  • 2 teaspoons vanilla extract
  • 8 ounces tofu cream cheese, room temperature
For the Purple Frosting:
  • 1 cup (2 sticks, 8 ounces) unsalted butter, room temperature
  • 8 ounces cream cheese, room temperature
  • 6 to 8 cups powdered sugar
  • ¼ teaspoon fine salt
  • 1 tablespoon vanilla extract
  • Purple food gel
  • ¼ cup heavy cream
For assembling the Purple Sweet Potato Cake:
  • White Frosting
  • Purple Sprinkles
To make the Purple Sweet Potato Cake:
  1. Preheat oven to 350 degrees F. Grease three 8-inch cake pans with baking spray, set aside.
  2. Whisk flour, baking powder, baking soda, and salt together, set aside. Beat sugar, mashed purple sweet potato, and purple food gel until smooth and lump free, about 4 minutes on medium speed. Scrap bowl and paddle as needed. Add oil, continuing to beat until combined. Beat eggs in one at a time. In a spouted measuring cup, whisk together buttermilk, sour cream, and vanilla.
  3. With mixer on low add dry-ingredients in 3 additions alternately with wet-ingredients in 2 additions, beginning and ending with dry-ingredients. Give batter a few stirs by hand to ensure even incorporation.
  4. Divide between prepared pans and bake for 20 to 26 minutes, rotating halfway. The cakes will begin to pull away from the pans and a toothpick inserted will come out with a few moist, not wet, crumbs. Let cakes cool in pans for 5 minutes. Invert onto a wire rack to cool completely. If making ahead of time, wrap in plastic wrap and refrigerate until you're ready to assemble.
To make the Whipped Tofu Frosting:
  1. Whip heavy cream in a stand mixer fitted with a paddle attachment. Once medium peaks form, add vanilla and granulated sugar until medium-stiff peaks form, transfer into another bowl.
  2. Fit stand mixer with a paddle attachment. Beat butter until smooth, about 1 to 2 minutes on high, scrap sides and bottom of bowl down. Add powdered sugar and beat until smooth and lump free, beat in salt and vanilla. With mixer of low, add tofu cream cheese, beating until just combined. Once tofu cream cheese is incorporated, don't over beat filling. Fold in whipped cream by hand. Refrigerate until ready to assemble.
To make the Purple Frosting:
  1. Cube butter and cream cheese, and add into a stand mixer fitted with a paddle attachment. Beat at medium-high speed until smooth and lump free, about 3 minutes. Scraping the bowl and paddle as needed. Gradually add powdered sugar followed by salt, vanilla, vanilla, and food gel. Raise speed to medium-high and beat until aerated, another 3 minutes. Add heavy cream as needed, a few teaspoons at a time, to achieve the right consistency.
To assemble the Purple Sweet Potato Cake:
  1. Apply a bit of frosting onto a cake board and secure the first cake layer. Pipe a boarder of white frosting around perimeter, fill center with Whipped Tofu Filling. Stack second cake layer on, repeat frosting and filling process and top with the final third layer. Lightly apply a dirty layer of purple frosting. Refrigerate for 15 minutes, apply a thicker layer of purple frosting. Apply sprinkles and pipe with remaining white frosting.
Cake adapted from Yummy Medley , filling and frosting by Layer Cake Parade
Recipe by Layer Cake Parade at http://layercakeparade.com/purple-sweet-potato-cake/