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Some desserts make you sigh happily after just one bite, and Chocolate Fudge Bumpy Cake is definitely one of them.
Imagine a moist chocolate cake with sweet, creamy “hills” of buttercream and a rich fudge topping draped over the top of the cake. Let’s dig into this Bumpy Cake!
It’s like a birthday party for your taste buds, even if there’s no special occasion. Who needs an excuse for a delicious dessert like this?
What’s funny is how something so fancy-looking can be pretty easy to make. Sure, it’s got a few steps—there’s the devil’s food cake base, a buttercream layer you “bump” across the top, and then a silky chocolate fudge frosting to cover it all.
But don’t let that scare you. In this recipe, you’ll whip up a rich devil’s food cake with coffee (for flavor), create the simplest vanilla buttercream, and then pour a fudge topping over everything.
The bumps of buttercream might remind you of snowy hills, or maybe little speed bumps—hence the name. Either way, they’re fun, delicious, and will make your dessert table look extra inviting.
So if you’re craving something sweet and a bit over-the-top, say hello to your new baking project.
It’s got chocolate, it’s got fluff, it’s got style—and it’ll leave your friends saying, “Is that store-bought?” You can grin and say, “Nope, made it myself!” Let’s get started on some bumpy cake, shall we?
Some of our other favorite Cake Recipes we have on our site include: Woolworth Cake Recipe (No-Bake Cheesecake), Layer Chocolate Turtle Cake Recipe, and Chocolate Caramel Snickers Cheesecake Recipe.
Jump to:
- WHY THIS RECIPE WORKS:
- INGREDIENTS NEEDED (SCROLL TO THE BOTTOM OF THIS POST FOR THE FULL RECIPE CARD):
- HOW TO MAKE bumpy cake:
- FREQUENTLY ASKED QUESTIONS ABOUT THIS RECIPE:
- DO I HAVE TO ADD THE COFFEE?
- DOES THIS NEED TO BE REFRIGERATED?
- ANY ADDITIONS?
- ANY SUBSTITUTIONS?
- HOW TO STORE:
- DANA’S TIPS AND TRICKS:
- Chocolate Fudge Bumpy Cake Recipe
WHY THIS RECIPE WORKS:
- Layers of Flavor: You get a devil’s food cake that’s moist and chocolatey, plus buttercream bumps on top, and then a smooth chocolate fudge frosting – no candy thermometer needed!
- Simple Steps, Wow Results: Even though it looks fancy, the directions are pretty straightforward.
- Fun Presentation: The “bumpy” look sets it apart from regular cakes.
INGREDIENTS NEEDED (SCROLL TO THE BOTTOM OF THIS POST FOR THE FULL RECIPE CARD):
- All-purpose flour
- Unsweetened cocoa powder
- Fine sea salt
- Baking soda
- Granulated sugar
- Light brown sugar
- Vegetable oil
- Eggs
- Buttermilk
- Vanilla extract
- Coffee
- Water
- Unsalted butter
- Powdered sugar
- Dark corn syrup
HOW TO MAKE bumpy cake:
- Preheat the oven to 350°F. Spray a 9×13 baking dish with baking spray, set aside.
- In a large bowl whisk together the flour, cocoa powder, salt, baking soda, sugar, and brown sugar until combined.
- In a medium-sized bowl whisk together the oil, eggs, buttermilk, and vanilla until smooth.
- Add the wet ingredient to the dry and stir it together until there are no dry patches.
- Place the coffee and water in a small sauce pot and bring to a boil. I like to add slightly more than the recipe calls for because some will evaporate.
- Once at a boil, measure out ⅔ cup into a heat-proof measuring cup and then pour it into the batter.
- Gently whisk until smooth, be careful not to splash because the liquid mixture is very hot, this may take a few minutes.
- Pour into the prepared baking dish. Bake for 30-35 minutes until a toothpick inserted into the center comes out clean.
- Let cool completely on a wire rack. Once cool, place it into the freezer for 1 hour.
- While the cake is freezing, make the filling. Place the butter in a medium-sized bowl. Add the powdered sugar a little at a time using an electric hand mixer until fully combined. The mixture will be thick.
- Add the salt, vanilla, and milk. Whisk to combine. Turn the mixer on medium-high and whip for 3 minutes until fluffy. It will still be thick, that’s okay.
- Place the filling into a piping bag or a gallon-sized plastic bag. Cut a corner of the bag so there is about ½ inch opening. Pipe 7 thick rows of the filling across the shorter side of the cake, about 1 inch apart.
- Place back in the freezer for at least 30 minutes or longer until the filling is frozen.
- Once the filling is frozen, make the topping. Place half of the butter into a medium-sized saucepan along with the buttermilk, cocoa powder, corn syrup, and salt. Place over medium heat and whisk constantly until it comes to a low boil, reduce the heat to low, and simmer for 3 minutes, while still whisking constantly.
- Take off the heat and whisk in the remaining butter, one tablespoon at a time until mixed in. Slowly add the powdered sugar a spoonful at a time and whisk until smooth. Add the vanilla and whisk that in.
- Take the cake out of the freezer and pour the topping over everything. I like to concentrate the topping over the bumps to make sure they are coated, then pour the remaining topping all over the cake.
- Place back in the freezer for 15 minutes or until the topping is fully set. Slice and serve immediately.
FREQUENTLY ASKED QUESTIONS ABOUT THIS RECIPE:
DO I HAVE TO ADD THE COFFEE?
Not at all.
The coffee just deepens the chocolate flavor—you won’t taste it as “coffee.” But if you’re not into java, feel free to replace it with hot water.
Your cake will still be delicious.
DOES THIS NEED TO BE REFRIGERATED?
After you pour the fudge on and let the cake cool, it’s best to store it in the fridge to keep the buttercream bumps from melting.
But you can take it out and let it come to room temperature before serving, so it’s nice and soft.
ANY ADDITIONS?
Want to kick your Chocolate Fudge Bumpy Cake up a notch? Here are 10 fun ideas:
- Sprinkle Crushed Cookies on top before the fudge sets for a crunchy twist.
- Add Espresso Powder to the cake batter for extra bold chocolate flavor.
- Dust with Shredded Coconut over the fudge for a tropical vibe.
- Garnish with Chopped Nuts (walnuts or pecans) to add a little crunch.
- Decorate with Chocolate Chips or candy pieces if you’re feeling fancy.
- Pipe Whipped Cream rosettes around the edges for that bakery look.
- Drizzle a Caramel Sauce over the fudge topping if you like a sweet-salty combo.
- Sprinkle Sea Salt lightly on top for a salty surprise in each bite.
- Mix Cinnamon into the cake batter for a subtle spice factor.
- Add a Scoop of Vanilla Ice Cream when serving for an extra sweet bite.
ANY SUBSTITUTIONS?
Need to tweak the recipe? Here are six quick swaps:
- Regular milk for the buttermilk if that’s all you have (try adding a tablespoon of white vinegar to mimic buttermilk tang).
- Brown sugar can be replaced with all granulated sugar if you’re out—though you might lose a little depth of flavor.
- Hot water instead of coffee for the wet ingredients portion—your cake won’t have that coffee undertone, but it’ll still be yummy.
- Corn syrup can be switched for golden syrup or honey if you prefer.
- Coconut oil in place of vegetable oil for a subtle coconut taste.
- Gluten-free flour blend to replace all-purpose flour if someone in your household avoids gluten.
HOW TO STORE:
Refrigerator:
Place leftovers in an airtight container (or cover the cake pan with plastic wrap).
The cake will keep for up to 5 days in the fridge.
When you’re ready to enjoy another slice, let it sit out for 15–20 minutes so the icing softens.
Freezer:
Yes, you can freeze this!
Wrap slices tightly in plastic and foil, then store for up to 3 months.
Thaw it overnight in the fridge, and it’ll be ready to devour the next day.
DANA’S TIPS AND TRICKS:
- Let the Cake Cool: Trying to add buttercream or fudge when the cake is still hot will cause a melty mess, so be patient.
- Use a Piping Bag: It’s the easiest way to create those “bumpy” ribbons of vanilla buttercream across the cake. A large round tip works great.
- Watch the Heat: When making the fudge topping in a medium saucepan over medium-high heat, stir constantly so it doesn’t scorch.
- Avoid Overmixing: Once you add the wet ingredients to your dry ingredients, stir until just combined. Overmixing can give you a denser cake.
- Use Good Cocoa Powder: A high-quality unsweetened cocoa powder can make a big difference in flavor, so pick your favorite brand.
- Reheat for a Hot Fudge Touch: If the cake is cold, try warming your slice for a few seconds in the microwave to get that gooey vibe again.
And there you have it—a Bumpy Cake that’s both fun to make and super delicious.
It’s got everything we love about a classic chocolate cake, plus the added surprise of those adorable buttercream bumps!
If you like this recipe, you might also like:
Chocolate Fudge Bumpy Cake Recipe
Ingredients
For the cake:
- 2 cups all-purpose flour
- ½ cup unsweetened cocoa powder
- 1 ½ teaspoons fine sea salt
- 1 ½ teaspoon baking soda
- 1 ½ cup granulated sugar
- 1/2 cup light brown sugar packed
- 1/2 cup vegetable oil
- 2 large eggs room temp
- 1 cup buttermilk room temp
- 1 tablespoon vanilla extract
- ⅓ cup coffee
- ⅓ cup water
For the filling:
- ½ cup unsalted butter
- 2 ½ cups powdered sugar
- Pinch of fine sea salt
- 1 teaspoon vanilla extract
- 1 ½ tablespoons whole milk
For the chocolate topping:
- ¾ cup unsalted butter cut into tablespoons, divided
- ½ cup buttermilk
- ½ cup cocoa powder
- ¼ cup dark corn syrup
- ½ teaspoon fine sea salt
- 3 cups powdered sugar
- 1 ½ teaspoons vanilla extract
Instructions
- Preheat the oven to 350°F. Spray a 9×13 baking dish with baking spray, set aside.
- In a large bowl whisk together the flour, cocoa powder, salt, baking soda, sugar, and brown sugar until combined.2 cups all-purpose flour, ½ cup unsweetened cocoa powder, 1 ½ teaspoons fine sea salt, 1 ½ teaspoon baking soda, 1 ½ cup granulated sugar, 1/2 cup light brown sugar
- In a medium-sized bowl whisk together the oil, eggs, buttermilk, and vanilla until smooth.1/2 cup vegetable oil, 2 large eggs, 1 cup buttermilk, 1 tablespoon vanilla extract
- Add the wet ingredient to the dry and stir it together until there are no dry patches.
- Place the coffee and water in a small sauce pot and bring to a boil. I like to add slightly more than the recipe calls for because some will evaporate.⅓ cup coffee, ⅓ cup water
- Once at a boil, measure out ⅔ cup into a heat-proof measuring cup and then pour it into the batter.
- Gently whisk until smooth, be careful not to splash because the liquid mixture is very hot, this may take a few minutes.
- Pour into the prepared baking dish. Bake for 30-35 minutes until a toothpick inserted into the center comes out clean.
- Let cool completely on a wire rack. Once cool, place it into the freezer for 1 hour.
- While the cake is freezing, make the filling. Place the butter in a medium-sized bowl. Add the powdered sugar a little at a time using an electric hand mixer until fully combined. The mixture will be thick.½ cup unsalted butter, 2 ½ cups powdered sugar
- Add the salt, vanilla, and milk. Whisk to combine. Turn the mixer on medium-high and whip for 3 minutes until fluffy. It will still be thick, that’s okay.Pinch of fine sea salt, 1 teaspoon vanilla extract, 1 ½ tablespoons whole milk
- Place the filling into a piping bag or a gallon-sized plastic bag. Cut a corner of the bag so there is about ½ inch opening. Pipe 7 thick rows of the filling across the shorter side of the cake, about 1 inch apart.
- Place back in the freezer for at least 30 minutes or longer until the filling is frozen.
- Once the filling is frozen, make the topping. Place half of the butter into a medium-sized saucepan along with the buttermilk, cocoa powder, corn syrup, and salt. Place over medium heat and whisk constantly until it comes to a low boil, reduce the heat to low, and simmer for 3 minutes, while still whisking constantly.¾ cup unsalted butter, ½ cup buttermilk, ½ cup cocoa powder, ¼ cup dark corn syrup, ½ teaspoon fine sea salt
- Take off the heat and whisk in the remaining butter, one tablespoon at a time until mixed in. Slowly add the powdered sugar a spoonful at a time and whisk until smooth. Add the vanilla and whisk that in.3 cups powdered sugar, 1 ½ teaspoons vanilla extract
- Take the cake out of the freezer and pour the topping over everything. I like to concentrate the topping over the bumps to make sure they are coated, then pour the remaining topping all over the cake.
- Place back in the freezer for 15 minutes or until the topping is fully set. Slice and serve immediately.
Notes
- Let the Cake Cool: Trying to add buttercream or fudge when the cake is still hot will cause a melty mess, so be patient.
- Use a Piping Bag: It’s the easiest way to create those “bumpy” ribbons of vanilla buttercream across the cake. A large round tip works great.
- Watch the Heat: When making the fudge topping in a medium saucepan over medium-high heat, stir constantly so it doesn’t scorch.
- Avoid Overmixing: Once you add the wet ingredients to your dry ingredients, stir until just combined. Overmixing can give you a denser cake.
- Use Good Cocoa Powder: A high-quality unsweetened cocoa powder can make a big difference in flavor, so pick your favorite brand.
- Reheat for a Hot Fudge Touch: If the cake is cold, try warming your slice for a few seconds in the microwave to get that gooey vibe again.
Nutrition
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