Bumpy Cake is a true Detroit original and a beloved piece of Midwestern dessert history. Made famous by Sanders Candy, this rich chocolate cake is instantly recognizable by its signature “bumps”—rows of fluffy buttercream piped across the top and then smothered in a thick, glossy chocolate fudge icing. The contrast between the moist chocolate cake, creamy buttercream, and decadent fudge frosting makes every bite nostalgic, indulgent, and unforgettable. It’s not just a cake—it’s a slice of Detroit tradition.
Ingredients
For the Chocolate Cake
2 cups all-purpose flour
2 cups granulated sugar
¾ cup unsweetened cocoa powder
2 teaspoons baking soda
1 teaspoon baking powder
1 teaspoon salt
2 large eggs
1 cup buttermilk
½ cup vegetable oil
2 teaspoons vanilla extract
1 cup hot coffee or hot water
For the Buttercream “Bumps”
½ cup unsalted butter, softened
2 cups powdered sugar
2 tablespoons heavy cream or milk
1 teaspoon vanilla extract
Pinch of salt
For the Chocolate Fudge Icing
½ cup unsalted butter
½ cup heavy cream
¾ cup granulated sugar
½ cup unsweetened cocoa powder
1 teaspoon vanilla extract
Pinch of salt
Instructions
- Make the Cake
Preheat your oven to 350°F (175°C). Grease and flour a 9×13-inch baking pan.
In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt. Add the eggs, buttermilk, oil, and vanilla extract, and mix until smooth. Slowly stir in the hot coffee or water—don’t worry, the batter will be thin.
Pour the batter into the prepared pan and bake for 30–35 minutes, or until a toothpick inserted in the center comes out clean. Let the cake cool completely. - Prepare the Buttercream
In a bowl, beat the softened butter until creamy. Gradually add the powdered sugar, then mix in the cream, vanilla, and salt. Beat until light and fluffy.
Transfer the buttercream to a piping bag fitted with a round tip. Pipe long, thick lines (“bumps”) lengthwise across the top of the cooled cake. Place the cake in the refrigerator for 20–30 minutes to firm up the buttercream. - Make the Chocolate Fudge Icing
In a saucepan over medium heat, combine the butter, cream, sugar, cocoa powder, and salt. Stir constantly until the mixture is smooth and begins to gently boil. Let it boil for 1 minute, then remove from heat and stir in the vanilla extract.
Allow the fudge icing to cool slightly until thick but still pourable. - Assemble the Cake
Carefully pour the warm fudge icing over the chilled cake, spreading gently so it covers the buttercream bumps completely. Let the icing set at room temperature or refrigerate until firm.
Serving Tip
Slice with a sharp knife, wiping it clean between cuts for those beautiful layered slices. Serve with cold milk or coffee for the ultimate Detroit-style treat