you're making mealtime meaningful.
Bumpy Cake is a true Detroit classic, and if you grew up in the Motor City, chances are you know it well. This cake is most closely tied to Sanders, a Detroit-based candy and dessert company that first made it popular in the early 1900s. The iconic look comes from rows of buttercream piped across the top, then covered in a thick layer of chocolate fudge icing. Those “bumps” aren’t just for show—they’re what make this cake instantly recognizable and deeply nostalgic for many Michiganders.
At its heart, Bumpy Cake is a simple chocolate cake done right. We used devil’s food cake to keep things easy while still delivering a rich chocolate flavor. Once baked and cooled, the cake becomes a canvas for the buttercream, which is piped in straight lines across the top. Chilling the cake at this stage is key, since it helps the buttercream hold its shape when the warm fudge icing is poured on later.
The fudge icing is where this cake really takes things over the top. Made on the stovetop with butter, cocoa powder, buttermilk, and corn syrup, it comes together smooth, glossy, and super chocolatey. Pouring the icing over the chilled cake allows it to flow around the buttercream bumps without melting them away. As it sets, the icing forms that classic finish that fans of Bumpy Cake know and love.
This is the kind of dessert that’s perfect for sharing, whether it’s for a birthday, potluck, or holiday table. It slices cleanly, feeds a crowd, and delivers big chocolate flavor without being overly complicated. More than just a cake, Bumpy Cake is a piece of Detroit history—one that’s still just as good today as it was generations ago.
Bumpy Cake
Yield(s): Serves 12
40m prep time
25m inactive
you're making mealtime meaningful.
Cake
- 1 box devils food chocolate cake
- Eggs, oil, and water, according to box directions
Buttercream
- 4 tablespoons butter
- 1 1/2 cup powdered sugar
- 1/2 teaspoon vanilla extract
- 1 tablespoon milk
- Pinch of salt
Fudge Icing
- 1/2 cup buttermilk
- 2 tablespoons corn syrup
- 1/2 cup butter
- 2/3 cup unsweetened cocoa powder
- 3 1/2 cups powdered sugar
- Pinch of salt
- 1/2 teaspoon vanilla extract
Preparation
- Preheat oven to 350 degrees F and grease a 9x13-inch baking dish.
- Cake: Mix cake batter according to package directions and pour into the prepared baking dish. Bake for time directed on box. Once baked, allow cake to cool to room temperature.
- Buttercream: Add butter to a medium-sized mixing bowl and beat until smooth. Add salt, powdered sugar, milk, and vanilla, then mix until smooth. Transfer to a piping bag or plastic bag, then chill for 15 minutes. Cut a ¾ inch opening in the piping bag and pipe straight lines across cake about 1 inch apart. Place cake in freezer while you prepare the icing.
- Fudge Icing: Add buttermilk, corn syrup, butter, cocoa powder, and salt to a medium-sized saucepan and heat mixture until it comes to a simmer. Lower heat and continue simmering for 3 minutes, stirring often to prevent sticking. Mix in powdered sugar 1 cup at a time until smooth. Remove from heat and mix in vanilla. Allow icing to cool for 10 minutes.
- Remove cake from freezer and pour icing over the cake, fully covering the piped lines. Place cake in fridge for 30 before serving to allow icing to set.
Recipe adapted from Kingarthurbaking.com