Bumpy Cake

If you like Hostess cupcakes, you're going to love bumpy cake. It's got a rich chocolate fudge taste and a funny look that makes this nostalgic cake recipe a charming addition to your recipe box. Created by Detroit, Michigan, chocolate company Sanders Chocolates in 1913, this dessert was originally known as "The Sanders Devil's Food Buttercream Cake," but Fred Sanders changed the name after customers started asking simply for the "bumpy cake."

What is Bumpy Cake?

Essentially, the bumpy cake is a devil's food cake with vanilla buttercream bumps covered with hot fudge frosting. There are a few steps, though, that you need to follow to give it the delightful bumpy shape.


How to Make Bumpy Cake

Start by preheating your oven to 375°F and prepping a 9 by 13 inch cake pan with butter and cocoa powder. In a mixing bowl (you can use a stand mixer or hand mixer) stir together the cocoa powder and coffee, then add the the rest of the ingredients (oil, buttermilk, baking soda, salt, vanilla extract, large eggs and granulated sugar) for the cake one by one, beating the mixture on medium speed for about 30 seconds after each ingredient. When you get to the all-purpose flour, add it slowly then mix for five minutes until the batter is lump free. The batter goes into the prepared pan; bake for 35-40 minutes.

When you take the cake out of the oven, let it cool on a wire rack. Important note number one: It's not a bumpy cake yet. Important note number two: Pop the whole cake into the freezer for at least an hour, though overnight is even better. If you're going for the shorter end of the freeze time, mix up the buttercream frosting next.

Beat the unsalted butter, heavy cream and vanilla together, then slowly add the powdered sugar and mix until the frosting is smooth. Take the cake out of the freezer, place the buttercream frosting in a pastry bag with a large round tip and pipe the frosting in lines about an inch apart across the top of the cake. Then, put the getting-bumpy cake back in the freezer for another hour.

To make the hot fudge icing, combine the sugar, cocoa, dark corn syrup, salt and butter in a saucepan and bring the mixture to a boil over medium high heat. While the mixture is cooking, whisk the buttermilk, confectioner's sugar and vanilla together in a large bowl. When the hot fudge reaches 240°F on a candy or instant read thermometer, take the pan off the heat and pour the hot chocolate mixture into the bowl with the buttermilk mixture, whisking constantly. Add the remaining butter and whisk until the frosting is smooth and only a little warm.

Now, put everything together. The still-pourable fudge goes over the cake so that it covers the buttercream completely. Tilt the baking pan to make sure the icing gets everywhere. The whole thing goes back in the freezer for 30 more minutes, then cut gently and serve your chocolate fudge bumpy cake!

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Bumpy Cake

This Detroit tradition is a delightfully rich chocolate fudge cake with two kinds of icing. When you cut it, you'll see why it's called bumpy cake.
Prep Time 3 hours
Cook Time 1 hour
Total Time 6 hours
Servings 12 servings



  • 1 tablespoon butter
  • 1/2 cup Dutch process cocoa powder plus 2 tablespoons for dusting pan
  • 1/2 cup freshly brewed hot coffee
  • 1/2 cup canola oil
  • 1 cup buttermilk
  • 1 tablespoon vanilla extract
  • 1 1/2 teaspoons baking soda
  • 1/2 teaspoon salt
  • 2 large eggs beat eggs before adding to batter
  • 2 cups sugar
  • 2 cups flour, all purpose


  • 1 stick butter softened slightly
  • 3 tablespoons heavy cream or whole milk
  • 1/2 teaspoon vanilla extract
  • 2 cups powdered sugar

Fudge Icing

  • 1/2 cup buttermilk
  • 2 1/2 cups powdered sugar
  • 1 teaspoon vanilla extract
  • 1 cup sugar
  • 1/3 cup Dutch process cocoa powder
  • 1/3 cup dark corn syrup
  • 1/4 teaspoon salt
  • 2 sticks butter cut into tablespoon-sized pieces


Make the cake batter

  • Preheat oven to 375°F. Grease a 9- by 13-inch cake pan with butter. Add cocoa powder to pan and shake to coat the pan. Shake out any excess cocoa.
  • Mix the cocoa and coffee in a mixing bowl using a stand mixer or hand mixer; beat on medium speed for 30 seconds. Add oil, mix for 30 seconds; add buttermilk, mix for 30 seconds; add baking soda, mix for 30 seconds; add salt, mix for 30 seconds; add vanilla, mix for 30 seconds; add eggs, mix for 30 seconds; add sugars, mix for 30 seconds. Add flour and mix about 5 minutes until the batter is lump free (though the batter will have bubbles in it).
  • Pour batter into the prepared pan and smooth it out with a spatula. Bake until cake tester comes out clean, 35 to 40 minutes. Transfer to a wire rack and allow to cool for at least 30 minutes. Transfer the cake to the freezer for at least an hour and up to overnight.

Mix the buttercream

  • In the bowl of your mixer, beat butter, heavy cream, and vanilla on medium low speed. With the mixer on low, slowly add powdered sugar, beating on low until just mixed. Increase speed to high and beat for one minute until smooth. Using a large round piping tip, pipe frosting in lines across the surface of the cake, an inch or so apart. Place cake back in the freezer for 30 minutes to an hour.

Make the fudge icing

  • In a large bowl whisk together buttermilk, confectioner's sugar and vanilla.
  • In a medium saucepan, combine, sugar, cocoa, corn syrup, salt and 1 stick worth of butter. Stir occasionally to fully incorporate butter as it's melting then bring mixture to a boil over medium high heat. Cook until the mixture is 240°F on a candy or instant read thermometer (a bit dropped into cold water will make a soft, malleable ball), then take off the heat.
  • Whisking constantly, pour the hot mixture into the buttermilk mixture. Add the remaining butter and continue whisking until the mixture is smooth and has cooled slightly.
  • Take the cake out of the freezer and pour the slightly warm frosting over the cake; cover buttercream rolls completely. The frosting will be thin, but will firm up when cool. Tilt the cake pan to get frosting everywhere. Return cake to freezer for at least 30 minutes more to set.
  • Serve chilled; a small paring knife works best to cut the cake. Store leftovers in refrigerator or freezer.


Recipe adapted from Food.com.


Calories: 1320kcalCarbohydrates: 194gProtein: 10gFat: 62gSaturated Fat: 33gPolyunsaturated Fat: 5gMonounsaturated Fat: 20gCholesterol: 167mgSodium: 347mgPotassium: 339mgFiber: 6gSugar: 151gVitamin A: 1600IUVitamin C: 0.8mgCalcium: 90mgIron: 2.3mg