Chocolate Heart Cake with Ganache Filling

If you know me, you know I love all things chocolate, from my chocolate souffle cheesecake to my chocolate covered strawberries, and chocolate banana bread. I’m always baking something to satisfy my sweet tooth. 

However, I try to make holidays a little extra special with fun themed treats, and this chocolate cake in heart shape is my go-to for Valentine’s Day. Despite its unique shape, it’s surprisingly simple to make, and the rich flavor is a chocolate lover’s dream come true. Just don’t say I didn’t warn you when it doesn’t last more than a day! 

Why you’ll love this recipe

• With simple steps, the preparation process is completely fuss-free. I promise you don’t need any special pans or equipment. As long as you have baking staples like round cake pans and a mixer, you’ll be on your way to baking a showstopping dessert!
• Everything comes together with simple ingredients. I use just a handful of simple ingredients for each layer, creating a bold, rich flavor with ingredients you likely have on hand and can easily find at any local grocery store. 
• The three layers make for a bakery-worthy treat. Bigger is always better, right? The combination of two chocolate cake layers, a silky ganache filling, and a fluffy buttercream topping creates a combination of tastes and textures that leaves guests practically licking their plates. 

As written, this chocolate heart cake makes enough for 10-12 generous slices, making it perfect for serving at a party! 

Key Ingredient Notes

For chocolate cake:

• Dutch-process cocoa powder – I use this over other types of cocoa powder to create a super-rich, chocolatey base. 
• Buttermilk – When combined with the cocoa powder, this helps create a moist, tender crumb that stays nice and soft, even after chilling or freezing. 
• Flour – I use all-purpose flour for the base of the cake, giving it structure. I haven’t tested this chocolate heart cake with other types of flour, and I can’t guarantee your results if you do. 
• Sugar – Two types of sugar, granulated sugar and brown sugar (light or dark), sweeten the cake batter, adding structure while keeping it moist and infusing it with a subtle molasses taste. Then, I use more granulated sugar to sweeten the chocolate Swiss buttercream frosting. 

For ganache filling:

• Heavy cream – This forms the base of the ganache, combining with the chocolate to create a silky consistency 
• Dark chocolate – I use dark chocolate for the ganache to add a rich taste without overpowering the cake, but semi-sweet chocolate also works well for a slightly sweeter taste. 
• Espresso powder – This doesn’t make your cake taste like coffee, but it does enhance the chocolate flavor of the ganache! If needed, you can omit it, but I highly recommend including it for a well-rounded taste. 

For chocolate Swiss buttercream:

• Egg whites – These create a light, fluffy meringue. I’ve tested this recipe with liquid egg whites, but I find that not all brands work for meringue. So, I recommend sticking with whole eggs and carefully separating them instead. Try these 9 delicious ways to use up extra egg yolks so that nothing goes to waste!  
• Semi-sweet chocolate – This creates a sweet, chocolate-flavored buttercream. Use either a chopped chocolate bar or chocolate chips. Or, swap the semi-sweet chocolate for dark chocolate for a bolder taste. 

How to make chocolate heart cake

1. Bake the cake

• Whisk the cocoa powder and hot water in a medium bowl until the cocoa is smooth and glossy. Then, set it aside to bloom. This enhances the taste and prevents the mixture from being clumpy in the cake! 
• Whisk the dry ingredients in a large bowl until well combined. 

• Add the wet ingredients to the bowl of dry ingredients, and whisk until smooth. 
• Pour in the bloomed cocoa mixture, and whisk to incorporate. The batter will be thin at this stage! 

• Divide the batter evenly between two 8-inch round cake pans greased with oil. 
• Bake until a toothpick inserted into the center comes out clean and the internal temperature registers about 200°F when measured with an instant-read thermometer. 
• Cool the cakes in the pans for a few minutes. Then, transfer them to a wire rack to cool completely. 

2. Make the ganache filling

• Heat the heavy cream in a small saucepan over medium heat just until it begins to steam. Do NOT let it come to a boil! 
• Remove the pan from the heat, and stir in the espresso powder, making sure it dissolves completely. 

• Pour the hot cream over the chopped chocolate in a heatproof bowl. Cover the bowl, and let the ingredients rest for a couple of minutes. Then, working from the center outward, stir to combine, creating a glossy consistency. 
• Add the butter, and stir to combine and emulsify. 

• Stir in the vanilla extract and salt. The ganache will look fluid, shiny, and cohesive! 
• Cool at room temperature until the mixture thickens to a spreadable consistency. We want it to be soft but not runny, kind of like warm Nutella. 

3. Prepare the Chocolate Swiss Meringue Buttercream

• Boil water in a small saucepan, and reduce the heat to a simmer. 
• Whisk the egg whites and sugar in a medium heat-proof bowl. I like to use my stand mixer! 
• Place the bowl over the saucepan of simmering water. 
• Cook the egg white mixture until the sugar melts completely and reaches a temperature of 160°F. 
• Remove the bowl from the heat, and whisk on medium speed, slowly increasing the speed to medium-high until stiff peaks form and the mixture is cool to the touch. This takes me about ten minutes with a stand mixer, but will likely take a little longer with a hand mixer! 
• Melt the chocolate according to the package instructions, and let it cool. 
• Scrape the sides of the bowl of whipped egg whites, and add salt. 
• Turn the mixer to medium speed, and add the butter one tablespoon at a time. Don’t worry if the buttercream starts to curdle. This is normal! 
• Whisk the buttercream until it’s smooth, light, and fluffy. 
• Switch the mixer to a paddle attachment, add the cooled melted chocolate, and beat to combine. 

4. Assemble the Chocolate Heart Cake

• Place two overlapping sheets of parchment paper on a serving plate, if not using a cake board, and place a cooled cake layer on top. 
• Pipe a buttercream dam around the edge of the cake. 
• Spoon ganache onto the center, spreading it gently up to the dam. Be careful not to press down! 
• Add the second cake layer, and chill the cake to set the filling. 

• Place a straight edge or ruler on the cake, and mark a straight line from the bottom upward along one side. Repeat this process, creating a line on the opposite side. 
• Cut along the lines to remove two rounded pieces of cake. You don’t have to be super precise here! The buttercream will hide any imperfections. 
• Attach the cut cake pieces to form the rounded top of the heart, using buttercream as a “glue”. Chill the cake again to help it set. 
• Cut a small V-shape for the heart’s valley. 
• Crumb coat the cake, and chill it again to set the top layer. 

• Spread buttercream over the cake, smoothing the sides and top. Add decorative piping or details as desired. 
• Remove the parchment strips, chill the cake, and enjoy! 

Don’t skip cooling the cake

This allows the layers to set and solidify, ensuring the cake holds its shape once sliced. 

Make Ahead Tips

Cake – Bake the cakes as instructed in the recipe card, and let them cool completely. Then, wrap them tightly in plastic wrap, and store them in the fridge for up to 2 days. Or, freeze them for up to 2 months. 

Ganache – Prepare the ganache up to 3 days in advance, storing it in an airtight container in the fridge. To use, let it come to room temperature, or gently warm it over medium heat until it achieves a soft, spreadable consistency. 

Buttercream – Store the buttercream covered in the fridge for up to 2 weeks or in a freezer-safe container in the freezer for up to 3 months. Thaw it at room temperature, and re-whip it until light and fluffy before using.

Storing Tips

Once assembled, you can transfer leftover cake to an airtight container or wrap it tightly with plastic wrap, followed by aluminum foil. It will keep fresh in the fridge for up to 3 days or in the freezer for up to 1 month. 

Thaw frozen chocolate heart cake in the fridge overnight, and enjoy it cold. Or, bring the cake to room temperature before serving. 

FAQs

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