This chocolate truffle cake is a super decadent chocolate layer cake. The cake layers are soft and moist filled with rich chocolate ganache. It's frosted with fluffy chocolate buttercream and decorated with Lindt chocolate truffles!
If you're a serious chocolate lover, this chocolate truffle cake is for you! The sponge is so fudgy and moist, and the layers are filled with rich chocolate ganache. The buttercream frosting is so smooth and chocolatey with store-bought chocolate truffles sprinkled on top, making this cake the ultimate decadent dessert!
This cake is perfect for any special occasion and will please all the chocoholics in your life. It's perfect for Valentine's Day or a birthday party. I actually made this cake for my sister's birthday. She's the biggest chocolate lover I know and was so impressed!
Why You'll Love This Chocolate Truffle Cake
- Moist, rich chocolate cake- The cake layers are flavorful, soft, and moist thanks to buttermilk and hot coffee! You also don't need a mixer or anything special to make the sponge.
- Chocolate ganache filling- The smooth, thick chocolate ganache filling mimics the filling of a Lindt chocolate truffle. It's chocolate heaven!
- Silky chocolate buttercream- I used the same whipped chocolate buttercream to frost my small batch chocolate cupcakes. I didn't whip it for this cake so it's super smooth and creamy.
- Chocolate truffles- Of course I had to top the cake with real chocolate truffles! You could even put homemade truffles on top, like these bourbon chocolate truffles.
Here are notes about some of the ingredients used. For quantities and full instructions, see the recipe card below.
Ingredients for the cake.
For the ganache filling.
For the buttercream.
- Oil- Making chocolate cake with oil helps it stay moist for a long time. Use a neutral, flavorless oil, like canola, avocado, or vegetable oil.
- Eggs- 2 large eggs add lift and bind the ingredients together. Take out of the fridge 1-2 hours before baking to reach room temperature.
- Buttermilk- Buttermilk's acid tenderizes the gluten strands and makes for a super soft cake. Take it out of the refrigerator 1-2 hours before baking.
- Vanilla- A splash of pure vanilla extract enhances the other flavors.
- All purpose flour- All purpose flour is best for a soft, tender texture. Weigh it in grams for accuracy.
- Granulated sugar- White sugar sweetens the cake and holds on to moisture.
- Cocoa powder- I recommend Dutch-processed cocoa powder. It's treated with alkali and has a more intense chocolate flavor than regular unsweetened cocoa powder.
- Baking powder & baking soda- These leaveners react with heat and acid, making the cake to rise and get fluffy in the oven. Make sure they aren't expired!
- Salt- A pinch rounds balances the sweetness and activates the leavening agents.
- Hot coffee- Hot brewed coffee blooms the cocoa powder to release all its flavor.
- Chopped chocolate- Use semi-sweet or bittersweet chocolate baking bars for the ganache. They're easier to melt than chocolate chips.
- Heavy cream- Use heavy whipping cream that is at least 35% fat to emulsify the chocolate and get the best ganache texture. It's also used to thin out the buttercream.
- Unsalted butter- Room temperature butter makes up the base of the chocolate buttercream.
- Powdered sugar- Also called confectioners or icing sugar, this sweetens the frosting and adds structure. You don't need to sift it.
Substitutions & Variations
- Buttermilk: Sub plain kefir for the buttermilk. Unfortunately you can't use sour cream or Greek yogurt because they're too thick. There are homemade buttermilk substitutes out there, but I don't recommend them since they aren't strong enough for this cake.
- All purpose flour: Use 1-to-1 Gluten Free Baking Flour for a gluten free cake.
- Coffee: This cake is also delicious made with boiling water if you don't have coffee on hand.
- Heavy cream: Coconut cream is the best substitute. Use the liquid part, not the solid stuff at the top of the can.
- Use your favorite dairy free butter, cream, and buttermilk to make this cake dairy free.
- You can leave off the Lindt truffles completely or use Ghirardelli bars, Dove bars, chocolate flakes, sprinkles, or your favorite chocolate candy.
Helpful Equipment & Tools
- You need 2 8-inch round cake pans. Use aluminum pans, not silicone or glass. The cake will burn in a silicone pan! I recommend non-stick pans. If yours aren't, spray with baking spray before lining with parchment rounds.
- For the frosting, you need an electric hand mixer or stand mixer fitted with the paddle attachment.
- An offset spatula and bench scraper are helpful for frosting the cake and spreading buttercream evenly.
- Use a revolving cake decorating stand or turntable to make decorating even easier! This holds the cake in place and rotates so you don't have to reach around it.
Step by Step Instructions
Before you start baking, preheat the oven to 350°F/180°C. Spray two 8-inch cake pans with baking spray and line with parchment paper. Set aside.
STEP 1: First, whisk the oil, eggs, buttermilk, and vanilla together in a large mixing bowl vigorously.
STEP 2: Next, add the flour, sugar, cocoa powder, baking powder, baking soda, and salt to the wet ingredients. Gently whisk everything together until there are no lumps or dry patches.
STEP 3: Next, pour in the hot coffee and whisk the batter until silky and smooth. It will be very liquidy.
STEP 4: Evenly pour the batter into the lined pans and bake at 350°F/180°C for 25-30 minutes. The cakes are done when a toothpick inserted in the center comes out clean with a few moist crumbs attached.
STEP 5: Remove the cakes from the oven and let them cool in the hot pans for 5-10 minutes. Flip on to a wire cooling rack and let cool completely before frosting.
STEP 6: While the cake layers cool, make the ganache. Place chocolate in a large bowl and microwave the heavy cream in separate bowl for about 45 seconds. Pour the hot cream over the chocolate and let sit for 1 minute.
STEP 7: Whisk the chocolate and cream together until smooth. Place a piece of plastic wrap over the surface of the ganache to prevent a skin. Chill in the refrigerator for about 30 minutes until it reaches a thick, spreadable consistency.
STEP 8: To make the chocolate buttercream, beat softened butter on medium high speed in the bowl of a hand mixer or stand mixer until creamy.
STEP 9: Mix in the cocoa powder and salt on low speed, increasing to medium until well incorporated. Then gradually add the powdered sugar on low so it doesn't fly everywhere. Make sure to scrape the sides of the bowl periodically to get any lumps.
STEP 10: While mixing on low, stream in the vanilla and heavy cream until your desired consistency is reached.
STEP 11: To assemble, fit a piping bag with a large tip and fill with buttercream. Place one cake layer on a cake board and pipe a circle around the edges of the cake. This is a dam that keeps the filling inside and keeps the layers from sliding around.
Fill the center with ganache. Place the second cake layer on top with the bottom facing up to make the cake flat.
STEP 12: Apply a thin layer of frosting, or crumb coat, all over to lock in loose crumbs. Chill the cake in the freezer for 20 minutes or until the frosting is dry to the touch. Then apply the second layer of frosting, decorate with more piping and chopped chocolate truffles, and serve!
Expert Baking Tips
- Use room temperature dairy ingredients. The eggs and buttermilk have to be room temperature for a uniform texture. Take them out of the fridge 1-2 hours before baking.
- Measure the flour in grams. Flour is super easy to overmeasure and pack in a measuring cup, so weigh it in grams with a kitchen scale for the best results. You can use the spoon and sweep method if you don't have a scale. Gently spoon the flour into your measuring cup and swipe off the excess.
- Level the cake layers. If your chocolate cake layers are domed, cut the domes off with a serrated knife to make the cake more even.
- Use an oven thermometer. All ovens are different, so use an oven thermometer to make sure it's running at the correct temperature. It's easy to overbake the cake if your oven is running hot!
Storage & Freezing
Store the cake in a large airtight container (like a cake carrier) in the refrigerator for up to 4 days. Let it sit on the counter for 30 minutes to reach room temperature before enjoying.
Any leftover ganache or frosting can be stored in separate airtight containers in the fridge for up to 4 days as well. Give the frosting a good mix before using again.
Freeze the chocolate truffle cake in individual slices. Tightly wrap each piece in plastic wrap and freeze in an airtight container or freezer bag for up to 2 months. I don't recommend freezing the unsliced cake because it takes up more space in the freezer and takes longer to thaw out.
Thaw the slices at room temperature for a couple hours before serving.
You can also make the cake layers ahead of time and freeze wrapped in cling film for up to 1 month! Let thaw for a couple hours in the fridge before assembling.
Frequently Asked Questions
You can use two 9-inch cake pans (the layers will be thin) or three to four 6-inch cake pans. You can also use two 8X8" or 9X9" square baking pans.
Of course! The recipe will make 20-24 cupcakes. You can use a piping tip to cut out the middles of the baked cupcakes and fill them with the ganache.
Yes, you can make the cake ahead of time! Once the layers are completely cool, wrap them tightly in plastic wrap and pop in the freezer for up to 30 days. Take them out 1 hour before decorating.
More Cake Recipes to Try
Chocolate Truffle Cake
- 113 grams chopped chocolate semi-sweet or bittersweet
- 113 grams heavy cream
Chocolate Buttercream Frosting
- 226 grams unsalted butter room temperature
- 65 grams cocoa powder
- ¼ teaspoon salt
- 450 grams powdered sugar
- ½ teaspoon vanilla extract
- 158 grams heavy cream room temperature
- 8 chocolate truffles optional
For the Cake
- Preheat the oven to 350°F/180°C. Spray two 8-inch cake pans with baking spray and line with parchment paper. Set aside.
- Whisk the oil, eggs, buttermilk, and vanilla extract in a large mixing bowl until well combined.148 grams neutral oil, 2 large eggs, 262 grams buttermilk, 2 teaspoon vanilla extract
- Add flour, sugar, cocoa powder, baking powder, baking soda, and salt to the wet ingredients. Gently whisk until smooth with no lumps.187 grams all purpose flour, 350 grams granulated sugar, 85 grams cocoa powder, 1 teaspoon baking powder, 1 teaspoon baking soda, 1 teaspoon salt
- Pour in hot coffee and whisk until the batter is smooth and thin.218 grams hot brewed coffee
- Evenly pour batter into the prepared pans. Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.
- Take the cakes out of the oven. Let them cool in their pans for 10 minutes before transferring to a wire rack to cool completely.
For the Ganache
- Place chopped chocolate in a large bowl. Microwave the heavy cream in a separate bowl for about 45 seconds.113 grams chopped chocolate, 113 grams heavy cream
- Pour the hot cream over the chocolate and let sit for 1 minute.
- Whisk the cream and chocolate together until smooth. Place plastic wrap on the ganache and refrigerate for 30 minutes or until the ganache reaches a spreadable consistency.
For the Buttercream
- Beat softened butter on medium high speed in the bowl of a hand mixer or stand mixer until pale and creamy.226 grams unsalted butter
- Mix in the cocoa powder and salt on low speed, increasing to medium until well incorporated65 grams cocoa powder, ¼ teaspoon salt
- Gradually add the powdered sugar in 2 additions on low so it doesn't fly everywhere. Scrape the sides of the bowl after each addition.450 grams powdered sugar
- Stream in the vanilla and heavy cream while mixing on low until the desired consistency is reached.½ teaspoon vanilla extract, 158 grams heavy cream
- Fit a piping bag with a large tip and fill with buttercream. Place one cake layer on a cake board and pipe a circle around the edges.
- Fill the center with ganache. Then place the second cake layer on top with the bottom facing up.
- Apply a thin layer of frosting (crumb coat) all over the cake. Chill in the freezer for 20 minutes or until the frosting is dry to the touch.
- Frost the rest of the cake, decorate with more piping and chocolate truffles, and enjoy!8 chocolate truffles