Decadent Bumpy Chocolate Cake

Bumpy Cake is a chocolate cake like no other, featuring thick stripes of vanilla buttercream piped across the top and covered in a glossy layer of rich fudge icing. These famous "bumps" create sweet pockets of frosting nestled under the fudge, adding a delightful texture and flavor that makes every bite unique. The fudgy topping sets into a soft shell, beautifully contrasting with the creamy buttercream and moist chocolate cake beneath. Together, they deliver a perfect balance of creamy, cakey, and chocolatey decadence that’s simply unforgettable.

I first made this for a family gathering, and it amazed everyone how the fuss-free buttercream bumps added so much charm and flavor. Now it’s a holiday tradition everyone looks forward to.

Ingredients

• All-Purpose Flour: for structure and tenderness Make sure to measure it accurately by spooning into your cup and leveling it off for best results
• Baking Soda: to give the cake a perfect rise Test freshness by dropping some into vinegar to check for bubbling
• Unsweetened Cocoa Powder: natural kind adds deep, old-fashioned chocolate flavor
• Granulated Sugar: to sweeten and keep the cake moist Do not reduce sugar as it also helps with texture
• Unsalted Butter: softened to cream easily Provides rich flavor and tender crumb
• Eggs: at room temperature to blend smoothly into the batter If cold, soak briefly in lukewarm water to bring to temp
• Vanilla Extract: adds warmth and balances the chocolate Used also in buttercream and fudge icing for consistency
• Buttermilk: adds moisture and tang If you don't have it, mix 1 tablespoon lemon or vinegar with 1 cup milk and let sit five minutes
• Hot Coffee or Water: to blend the batter Hot coffee enhances the chocolate flavor wonderfully
• For Vanilla Buttercream:
• Unsalted Butter: softened for smooth creaming
• Vegetable Shortening: helps the frosting hold its shape essential for clean piping of bumps
• Powdered Sugar: sifted to create light, fluffy frosting
• Heavy Cream or Milk: just enough to reach pipeable texture
• For Fudge Icing:
• Heavy Cream: makes a creamy, pourable icing
• Granulated Sugar: dissolves fully while heating for smooth shiny finish
• Unsalted Butter: cut into pieces helps combine evenly
• Unsweetened Cocoa Powder: delivers bold chocolate color and flavor

Step-by-Step Instructions

Combine Dry Ingredients:

Mix flour, cocoa powder, baking soda, and salt thoroughly in a medium bowl to ensure even distribution of rising agents and chocolate flavor

Cream the Butter and Sugar:

In a large bowl, beat softened butter with sugar on medium speed until light and fluffy which generally takes about 3 to 5 minutes This step is important for creating a tender cake crumb Add eggs one at a time, beating well after each addition Then stir in the vanilla extract for warmth

Mix Wet and Dry Ingredients:

Alternately add dry ingredients and buttermilk to the butter mixture starting and ending with the dry ingredients Use a gentle folding method to avoid over mixing as that can toughen the cake

Add Hot Coffee or Water:

Slowly incorporate the hot liquid to the batter This thins it slightly for a moist texture and intensifies the chocolate flavor without tasting like coffee

Bake the Cake:

Pour the batter evenly into a greased 9-by-13-inch pan Bake at 350 degrees Fahrenheit for 30 to 35 minutes until a toothpick comes out clean Let cool completely on a wire rack to set the crumb

Prepare the Vanilla Buttercream:

Beat together softened butter and vegetable shortening until smooth and fluffy Gradually add sifted powdered sugar then mix in vanilla extract and salt Add cream gradually until the frosting holds its shape firmly enough to pipe but remains creamy

Pipe the Bumps:

Fill a piping bag fitted with a large round tip with buttercream Pipe long, thick stripes evenly spaced across the cooled cake Place the cake in the refrigerator for 30 minutes to firm the buttercream

Make the Fudge Icing:

In a saucepan over medium heat, combine cream, sugar, butter, cocoa powder, and a pinch of salt Stir continuously until the mixture thickens and sugar dissolves completely Remove from heat and stir in vanilla extract Let cool slightly so it’s warm but not hot enough to melt the buttercream

Pour the Fudge Over the Cake:

Gently pour the fudge icing over the chilled buttercream bumps allowing it to flow and coat the cake without spreading too much Use a slight tilting motion to encourage even coverage Chill the cake until the fudge sets

Serve:

Use a sharp knife heated in hot water and wiped dry before each slice for clean cuts Enjoy the rich combination of moist chocolate cake, creamy buttercream, and silky fudge icing

Save Pin

Storage Tips

Store the cake in an airtight container at room temperature for up to five days to keep the buttercream soft and the cake moist You can refrigerate it for up to a week but best to bring it back to room temperature before serving for the best texture Freeze wrapped tightly in plastic wrap and foil for up to three months Thaw completely at room temperature before slicing

Ingredient Substitutions

If you don’t have buttermilk mix one tablespoon lemon juice or vinegar with one cup of milk and let it rest for five to ten minutes This keeps the cake tender You can substitute coffee for hot water in the batter to amplify chocolate flavor without adding coffee taste Vegetable shortening in the buttercream can be replaced with additional softened butter for a more buttery flavor but the frosting may not hold the bumps as well

Serving Suggestions

Serve this cake with a simple scoop of vanilla ice cream or fresh berries to lighten the indulgence A drizzle of caramel sauce can add a wonderful contrast for special occasions Pair with a rich dark coffee or a glass of cold milk to balance the sweetness

Cultural and Historical Context

Bumpy Cake was created more than a century ago by Fred Sanders at Sanders Confectionery after running out of buttercream for his devil’s food cake Instead of a smooth layer, he piped thick rows of buttercream and covered the entire cake in fudge chocolate This creative solution became an instant hit and a beloved dessert that has stood the test of time especially in Detroit where it is considered a regional classic

Pro Tips

Make sure the cake is completely cool before piping buttercream or the frosting will melt and lose its shape Use a large round piping tip to get those perfect, even bumps Do not rush this step as uniformity enhances the cake’s signature look Let your fudge icing cool slightly before pouring it to avoid melting the buttercream but still pour while warm to get a glossy finish

Commonly Asked Questions

→ What makes the bumps in Bumpy Cake?

The bumps are thick stripes of vanilla buttercream piped across the cake, creating pockets of creamy sweetness beneath the fudge icing.

→ Why is coffee used in the batter?

Hot coffee enhances the chocolate flavor without adding a noticeable coffee taste, deepening the cake's richness.

→ How should the fudge icing be poured?

Let the fudge cool slightly before pouring over the buttercream bumps so it forms a soft shell without melting the frosting underneath.

→ Can I substitute buttermilk?

If you don't have buttermilk, mix lemon juice or vinegar with milk and let it sit for 5-10 minutes to create a tangy substitute.

→ What’s the best way to pipe the buttercream bumps?

Use a piping bag fitted with a large round tip for even, long stripes; a zip-top bag with a snipped corner works well too.

→ How do I store leftovers?

Keep the cake in an airtight container at room temperature for several days or refrigerate for up to a week; freezing is also an option.

[object Object]