Bumpy Cake

INGREDIENTS

For the cake:

  • Cooking spray

  • 2 cups unbleached all-purpose flour

  • 2 cups granulated sugar

  • 1/2 cup unsweetened cocoa powder (see Recipe Note)

  • 1 1/2 teaspoons baking soda

  • 3/4 teaspoon fine salt

  • 1 cup well-shaken buttermilk, at room temperature

  • 1/2 cup hot brewed coffee or hot water

  • 1/2 cup vegetable or canola oil

  • 2 large eggs

  • 2 teaspoons vanilla extract


For the icing:

  • 2 sticks (1 cup) unsalted butter, divided

  • 1 cup granulated sugar

  • 1/2 cup well-shaken buttermilk

  • 1/3 cup dark corn syrup

  • 1/3 cup unsweetened cocoa powder

  • 1/4 teaspoon fine salt

  • 1 cup powdered sugar

  • 1 teaspoon vanilla extract


For the filling:

  • 1 cup granulated sugar

  • 1/4 cup cornstarch

  • 1/8 teaspoon fine salt

  • 1 cup whole milk

  • 1 teaspoon vanilla extract

  • 8 tablespoons (1/2 cup) unsalted butter, at cool room temperature


INSTRUCTIONS

  1. Make the cake: Position a rack to the center of the oven and heat it to 350°F. Spray a 9 x 13-inch light-colored metal baking pan with cooking spray.

  2. In a large bowl, whisk together the flour, granulated sugar, cocoa powder, baking soda, and salt.

  3. In a medium bowl, whisk together the buttermilk, coffee or water, oil, eggs, and vanilla. Pour the wet ingredients in the dry. Beat with an electric mixer until smooth. Pour the batter into the prepared pan. Bake until a toothpick inserted in the center of the cake comes out clean, 30 to 35 minutes. Set the pan on a wire rack to cool completely. Meanwhile, prepare the filling.

  4. Make the filling: In a 2- to 2 1/2- quart saucepan, whisk together the granulated sugar, cornstarch, and salt. Whisk in the milk. Bring to a boil over medium-high heat; boil for 1 minute. Remove from the heat and whisk in the vanilla. Transfer to the clean bowl of an electric mixer and let cool completely. Beating with the paddle attachment on medium speed, beat in 1 tablespoon of butter at a time. Increasing the speed to medium-high, beat until light and fluffy and resembling whipped cream, about 5 minutes.

  5. When the cake has cooled completely, load the filling into a pastry bag fitted with a 1-inch large round tip. Pipe nine 9-inch lines crosswise over the cake, 1 inch apart. Freeze until the filling is solid, at least 30 minutes.

  6. Make the icing: When the filling is solid, keep the cake in the freezer while you prepare the icing: In a 2- to 2 1/2- quart saucepan, combine 1/2 cup of the butter and the sugar, buttermilk, corn syrup, cocoa powder, and salt. Place the pan over medium-high heat and bring the mixture to a boil. Clip a candy thermometer to the side of the pan and cook until the mixture reaches 235°F— no higher. Whisk in the remaining butter, 1 tablespoon at a time. Stir in the powdered sugar and vanilla, whisking until the icing is smooth.

  7. Remove the cake from the freezer. Immediately pour the icing in waterfall-like ribbons over the surface of the cake. If needed, gently rewarm any icing clinging to the pan, and pour it again. Freeze the cake until the icing is set, about 15 minutes, or refrigerate until ready to serve. Store any leftovers tightly covered in the refrigerator for up to a week.

RECIPE NOTES

Cocoa powder: My first choice here is a half-and- half mix of regular Dutch-processed and black cocoa powders, for dynamite color and flavor. But if all you have is natural cocoa, that will work, too.

Reprinted with permission from Midwest Made by Shauna Sever, Running Press, 2019.