This Chocolate Fudge Walnut Cake is a super moist and fluffy chocolate cake frosted with a creamy dark chocolate frosting. It’s stuffed walnuts and has a walnut topping and rich chocolate ganache drip.
This is the ultimate chocolate dessert. If you are a fan of the chocolate and walnut combo, take a look at these Dark Chocolate Walnut Brownies. Take a look at this Ganache Loaf Cake for another ultra-fudgy and super moist cake option. Serving a smaller crowd, this Mini Fudge Cake has you covered!
Why You NEED This Recipe
- Super moist and tender fudge cake made with oil, sour cream, and buttermilk
- Creamy dark chocolate fudge frosting
- Simple and rich chocolate ganache topping
- Crunchy walnut filling and topping for the ultimate texture and flavor
Moist Chocolate Cake Ingredients
- All Purpose Flour: Plain, white all purpose flour is perfect for this moist chocolate cake!
- Cocoa Powder: Cocoa powder is what creates the chocolate flavor in this cake. I use natural cocoa powder.
- Baking Soda & Baking Powder: Both leavening agents give this cake a rise and create a light and fluffy texture.
- Salt: Salt brings out sweetness.
- Granulated Sugar: Granulated sugar adds to sweetness, moisture, and structure!
- Eggs: You’ll need 2 large eggs at room temperature for this recipe. If you forget to leave the eggs out ahead of time, place them in a bowl of hot water for 5 minutes before using.
- Sour Cream: Room temperature sour cream creates a moister, softer cake.
- Buttermilk: Buttermilk at room temperature adds tenderness to the cake crumb.
- Vegetable Oil: Using oil in cake creates a moist cake that stays moist. You can substitute vegetable oil with any unflavored oil.
- Vanilla: Pure vanilla extract rounds out the flavor.
- Water: Hot water brings out the chocolate flavor while creating a smoother batter.
- Walnuts: Chopped walnuts are folded into the cake batter for extra flavor and texture.
Step by Step Process
STEP 1: Preheat your oven to 350 degrees Fahrenheit. Line 2 8-inch round pans with parchment paper and spray with cooking spray to ensure the cakes come out of the pans cleanly.
STEP 2: In a medium bowl, use a wire whisk to mix all purpose flour, cocoa powder, baking soda, baking powder, and salt together until combined.
STEP 3: In a large bowl, whisk granulated sugar, room temperature eggs, room temperature sour cream, room temperature buttermilk, vegetable oil, and vanilla extract togoether until smooth.
STEP 4: Carefully, whisk about 1/3 of the dry ingredients into the wet ingredients. Then, add 1/2 of the hot water. Repeat this process of adding the dry ingredients and the hot water until you reach a smooth batter. Stir the walnuts into the batter.
STEP 5: Divide the batter between your two prepared pans. Bake the cake for 28-32 minutes or until the cakes are shiny on top, the centers spring back when poked quickly with your pointer finger, and a toothpick inserted into the center comes out clean. Allow the cakes to cool before removing from the pan.
STEP 6: Prepare the dark chocolate fudge frosting by mixing powdered sugar, cocoa powder, and unsalted butter together on low speed until smooth. Beat heavy whipping cream into the frosting. Then, mix on high speed for 3 minutes to create a creamy chocolate frosting.
STEP 7: Top one of the cooled chocolate cake layers with the frosting. Then, push walnuts into the icing to create a walnut filling. Place the other cake layer on top of the walnuts.
STEP 8: Use the remaining frosting to frost the cake as desired.
STEP 9: Heat heavy cream in a small saucepan over medium heat until it just begins to bubble. Pour the heavy cream on top of a bowl of chocolate chips. Push the chocolate chips below the heavy cream because the chocolate may not fully melt if it is not fully touched by the hot cream. Then, let the mixture sit for 2 minutes.
STEP 10: Stir the ganache with a wire whisk in the center of the bowl. As the mixture starts to combine, slowly stir in a larger circle. Continue this process until you reach the outside rim of the bowl.
STEP 11: Pour the ganache on top of the cake, slightly pushing the chocolate over the edges to create a ganache drip on the cake. Top the cake with walnuts as desired.
Frequently Asked Questions
You can make this cake into 3 6-inch layers, a 9×13 inch sheet pan, or 2 9-inch rounds. You’ll need to adjust the baking time, so keep an eye on the cakes as they bake to avoid overbaking.
Buttermilk creates a light, tender, and ultra-soft crumb. I do not recommend using regular milk. You can make homemade buttermilk by adding 1 tablespoon of white vinegar or lemon juice to a liquid measuring cup. Then, add regular dairy milk to the measuring cup to reach 1 cup. Stir the mixture and let it sit for 5 minutes before using.
Store this cake at room temperature tightly covered or in an airtight container for up to 2 days, in the fridge for up to 4 days, or in the freezer for up to 4 months.
Ganache Drip Tips
Let the chocolate chips and heavy cream sit: For a smooth, rich chocolate ganache, let the hot heavy cream and submerged chocolate chips sit in the bowl for 2 minutes before mixing.
Use a piping bag or plastic bag: For more control over the chocolate drip, transfer the ganache to a piping bag or a zippable plastic bag that you will cut the corner off of to make a makeshift piping bag.
Push the ganache over the sides: Carefully push a dollop of ganache over the edge of the cake to let it drip down the side. The more ganache you add toward the edge, the thicker the drizzle will be.
Don’t let the ganache harden: After you have made the ganache, do not let it sit for longer than 10 minutes. It will harden and firm up, and you will not be able to spread it like a glaze to create the drip.
Expert Tips & Tricks
- Coat the pans: Make sure to line your baking pans with parchment paper before heavily spraying with cooking spray. This ensures the cakes come out cleanly after baking.
- Room temperature ingredients: For the lightest, fluffiest, and moistest chocolate cake, use room temperature eggs, sour cream, and buttermilk.
- Mixing: Do not overmix when adding the dry ingredients to the large bowl of wet batter because you will risk baking a dry and dense cake.
- Level the cakes: If you want a super flat cake, use a knife or leveling tool to remove the domes on the cakes before stacking and frosting.
- Freezing: To freeze this cake, pop it in the freezer uncovered for 45 minutes. Then, wrap it in plastic cling wrap in a few layers to preserve its freshness. Store it in the freezer for up to 4 months and bring to room temperature before slicing and serving.
This Chocolate Fudge Walnut Cake is a super moist and fluffy chocolate cake frosted with a creamy dark chocolate frosting. It’s stuffed walnuts with a walnut topping and rich chocolate ganache drip.
For the Chocolate Cake
- 1 3/4 cup (245g) all purpose flour
- 2/3 cup (56g) cocoa powder
- 2 teaspoons (10g) baking soda
- 1/2 teaspoon (2g) baking powder
- 1 teaspoon (5g) salt
- 1 3/4 cup (363g) granulated sugar
- 2 large eggs (100g), room temperature
- 1/2 cup (130g) sour cream, room temperature
- 1 cup (225g) buttermilk, room temperature
- 1/2 cup (100g) vegetable oil
- 1 teaspoon (4g) vanilla
- 3/4 cup (160g) hot water
- 1 cup (113g) walnuts, crushed
For the Dark Chocolate Fudge Frosting
- 1 1/2 cup (325g) unsalted butter, room temperature
- 2/3 cup (54g) unsweetened dark chocolate cocoa powder
- 3 cups (360g) powdered sugar
- 1/3 cup (80g) heavy cream, room temperature
For the Ganache
- 3/4 cup (180g) heavy whipping cream
- 1 1/2 cups (270g) semi sweet chocolate chips
For the Decoration
- 1 cup (113g) walnuts, chopped
For the Chocolate Cake
- Preheat your oven to 350 degrees. Line 2 8-inch round pans with parchment paper and heavily spray with cooking spray to prevent the cakes from sticking and breaking when removing them after baking and cooling.
- In a medium bowl, whisk all purpose flour, unsweetened cocoa powder, baking soda, baking powder, and salt together.
- In a large bowl, whisk granulated sugar, room temperature eggs, room temperature sour cream, room temperature buttermilk, vegetable oil, and pure vanilla extract together until fully combined and smooth.
- Alternate adding the dry ingredients and boiling water to the large bowl of wet ingredients. Start and end with the dry ingredients, beating them into the batter int 3 additions total. Whisk only until the dry ingredients disappear, as overmixing will lead to drier cake.
- Fold crushed walnuts into the batter.
- Divide the batter evenly between the two pans.
- Bake the cakes for 26-32 minutes or until a toothpick inserted into the center of the cake comes out with moist crumbs and the top springs back when poked in the center with your pointer finger.
- Let cakes cool in the pan for at least 20 minutes before transferring to a wire cooling rack to finish cooling.
For the Dark Chocolate Frosting
- In a large bowl with a hand mixer or in the bowl of a stand mixer fitted with a paddle attachment, beat room temperature butter until smooth.
- Slowly, add powdered sugar and dark cocoa powder into the butter. Beat on low speed, adding the powdered sugar and cocoa powder in small increments to avoid a big mess.
- Pour heavy cream into the frosting and beat on high speed for at least 3 minutes. This creates a light, velvety frosting.
- Place one layer of the chocolate cake on a cake stand or plate. Frost the top of it the dark chocolate icing.
- Place crushed walnut on top of the layer of frosting before adding the second cake layer.
- Frost the outside of the cake with the remaining frosting.
For the Ganache
- Pour your chocolate chips into a glass bowl.
- In a small saucepan, heat heavy cream over medium heat until the mixture just starts to bubble.
- Pour the heavy cream on top of the chocolate chips. Use a spoon to push the chocolate chips below the heavy cream to ensure all parts of the chocolate are touched by the hot cream.
- Allow the chocolate chips and hot cream to sit for about 2 minutes.
- Using a wire whisk, start mixing by making small circles in the center of the bowl. Continue making a swirl motion and slowly begin working outside the center of the bowl as the mixture combines.
- Do not let the ganache sit for longer than 10 minutes.
- Pour the ganache on top of the cake.
- Use a spoon to push the ganache over the edge of the cake to create the drips.
- Top the cake with additional chopped walnuts as desired.
- Store in an airtight container or tightly covered at room temperature for up to 2 days, in the fridge for up to 4 days, or in the freezer for up to 4 months.
Measuring Properly: Use a kitchen scale for most accurate measuring. When measuring flour, spoon it from the container into your measuring cups before using a knife to sweep across the top of the measuring cup to level it.
Baking Time: Be careful not to overbake the cake. The top should look domed, shiny, and the center should spring back when poked quickly with your pointer finger. A toothpick inserted into the center should come out with moist crumbs.
Cooling: Do not remove the cakes, stack them, or frost them until they have fully cooled.
Keywords: Chocolate Walnut Cake, Dark Chocolate Frosting, Ganache Drip Cake, Simple Cake, Moist Cake