Bumpy Cake Is an Iconic Michigan Dessert You Need to Try

Updated: Nov. 15, 2023

This is one cake where lumps and bumps are welcome, encouraged and downright delicious!

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When it comes to baking, most of the time you’re striving for a smooth and polished-looking cake. In Michigan, however, that’s not always the case. Meet Bumpy Cake, a delicious dessert recognized for its iconic fudge-covered buttercream bumps. This cake has a cult following and it’s clear why. It’s essentially a giant Hostess cupcake in the form of a sheet cake!

Where Is Bumpy Cake From?

To track down the history of Bumpy Cake, we need to travel to the original Sanders chocolate shop in Detroit, Michigan. The famous Bumpy Cake was born here when founder Fred Sanders created this iconic-looking cake in 1913. Originally known as “The Sanders Devil’s Food Buttercream Cake,” the name has evolved over the years thanks to loyal customers who lovingly called it “the cake with the bumps,” which caused Mr. Sanders to change the name to “Bumpy Cake.”

Today, Sanders sells four different varieties of Bumpy Cake. And, while they remain the sole owner of the original recipe and trademarked “Bumpy” name, we like to think our recipe for homemade Bumpy Cake is a good substitute if a trip to Michigan isn’t in the cards.

How to Make Bumpy Cake at Home

This recipe makes 9-12 servings.

Ingredients

Devil’s Food Cake:

  • 1/2 cup (1 stick) unsalted butter, room temperature
  • 3 tablespoons vegetable oil
  • 1 cup sugar
  • 1 large egg, room temperature
  • 2 large egg whites, room temperature
  • 1/2 tablespoon vanilla extract
  • 1-1/2 cups cake flour
  • 1 teaspoon baking powder
  • 1/2 teaspoon salt
  • 1/2 cup buttermilk, room temperature
  • 2 teaspoons instant espresso powder
  • 1/2 cup unsweetened cocoa powder, a 50/50 mix of regular and dark cocoa powder is best

Chocolate Fudge Frosting:

  • 1 cup (2 sticks) unsalted butter, divided
  • 1 cup granulated sugar
  • 1/2 cup buttermilk, shaken
  • 1/3 cup dark corn syrup
  • 1/3 cup unsweetened cocoa powder
  • 1/4 teaspoon salt
  • 1 cup confectioners’ sugar
  • 1 teaspoon vanilla extract

Vanilla Buttercream:

  • 1/2 cup (1 stick) unsalted butter, softened
  • 1-1/2 cups confectioners’ sugar, sifted
  • 1 tablespoon heavy whipping cream
  • 1 teaspoon vanilla extract
  • 1/8 teaspoon salt

Tools

  • Stand mixer: If you’re in the market for a stand mixer, this KitchenAid Artisan Series mixer is a great place to start. We love that it comes with a glass mixing bowl so you can easily see how well your dough or batter is mixing.
  • 8″ square baking pan: These 8×8-inch baking pans made by Taste of Home have an embossed design that strengthens the bakeware and increases airflow for even baking.
  • Cake decorating tool: Say goodbye to messy pastry bags with this fancy Dessert Decorating Tool by Wilton. It comes with four decorating tips, a fill tip and two couplers and can be used with most standard Wilton tips.

Directions

Step 1: Mix the cake batter

Preheat oven to 325°F. Grease an 8×8-in. square baking pan and line the bottom with parchment paper. In a stand mixer, cream butter, oil and sugar until light and fluffy, 5-7 minutes. Add eggs and egg whites, one at a time, beating well after each addition.

Next, in a separate medium bowl, whisk together the cake flour, cocoa powder, espresso powder, baking powder and salt. Then, gradually add the dry ingredients to the creamed mixture alternating with the buttermilk and mixing well after each addition. Last but not least, add the vanilla to the batter and mix until combined.

Editor’s Tip: If you don’t own a stand mixer, follow this recipe using a large bowl and an electric hand mixer.

Step 2: Bake the cake

Transfer the cake batter to your prepared baking dish. Spread the batter out evenly and bake for 30-40 minutes.

The cake is ready when a toothpick comes out clean when inserted into the center and the edges are gently pulling away from the sides of the pan. Remove promptly and let the cake cool completely in the pan on a wire rack. Transfer the cake to the freezer for at least an hour.

Having cake troubles? Here are some common cake mistakes and how to fix them.

Step 3: Prepare the buttercream

In the bowl of a stand mixer, beat butter until creamy. Next, slowly add the confectioners’ sugar, about 1/4 cup at a time, until smooth. Add the heavy cream, vanilla and salt and mix until fluffy; about 5-7 minutes. Transfer to a pastry bag fitted with an extra-large round tip and refrigerate until ready to use.

Step 4: Make the fudge frosting

In a large saucepan over medium heat, combine the butter, granulated sugar, buttermilk, dark corn syrup, cocoa and salt. Bring to a boil and cook for 2 to 3 minutes. Then, turn the heat to low and whisk in the confectioners’ sugar. Whisk until the sugar melts and the fudge is smooth with no lumps. Remove from heat and stir in the vanilla.

Transfer the fudge into a 4-cup glass measuring cup and let cool until just above room temperature. You want the fudge frosting to be warm enough to be pourable but cool enough so it doesn’t melt the buttercream when poured over the cake.

Step 5: Decorate

two slices of bumpy cake on white plates and a marble countertopLauren Habermehl for Taste of Home

Remove the cake from the freezer and the buttercream from the refrigerator. Pipe 3-4 thick ribbons of buttercream, running parallel and about 1-inch apart, over the entire length of the chilled cake. Return to the freezer for 20-30 minutes. Next, pour about half of the fudge icing evenly over the cake, covering the buttercream “bumps” completely. You can gently tip the pan from side to side to help the fudge flow smoothly over the entire cake.

Chill in the freezer for an additional 10 minutes and then pour the remaining fudge evenly over the top of the cake. Refrigerate the cake for 20-30 minutes to set the fudge completely before slicing into squares to serve.

Editor’s Tip: If the fudge cools too much before decorating, you may rewarm it in the microwave for 5-second bursts until it returns to a pourable consistency.

Different Flavors of Bumpy Cake

While devil’s food cake with buttercream and chocolate fudge frosting is the beloved classic, feel free to get creative with your Bumpy Cake flavors. Sanders itself makes Carrot Cake, Caramel and Vanilla Pecan.

Here are a few other flavor combos you can try: