Last updated on
The Ultimate Chocolate Cake – dark chocolate cake layers with chocolate mousse filling, chocolate buttercream, and chocolate drip.
It’s time for an oldie, but goodie recipe revisit! I first made this cake over three years ago for Westin’s 7th birthday and called it my Triple Chocolate Cake! It was actually one of the first cake recipes I posted to Cake by Courtney. Since it’s clearly been a long time since then, it was definitely time to revisit this recipe and bring it some life on the blog.
The chocolate cake layers are my beloved, go-to chocolate cake you’ll see in all my recipes with a chocolate cake element. When I first started making cakes from scratch over nine years ago, I felt it my mission to find the best chocolate cake recipe. I tried dozens and dozens. And while I liked several out there, I eventually developed my own that I now deem the best chocolate cake ever!
I love how moist, rich and flavorful this cake is – all without being overly sweet, thanks to the dark cocoa powder and not a lot of sugar. My favorite cocoa powder is Extra Brute Cacao Barry. But if you can’t get this, I also think Hershey’s Special Dark Chocolate cocoa powder is a great substitute. You’ll be able to find it at most grocery stores.
In between each cake layer, I decided to use a chocolate mousse filling. I wanted something a little lighter and a slightly different texture than the chocolate buttercream. To make the whipped cream filling stable enough to hold the layers, you’ll need to add some gelatin. As you do this, be careful to dissolve the gelatin fully in the heated cream or you’ll get chunks of gelatin in your filling. Yuck! Instead, we want a smooth and creamy texture.
You guys! This buttercream deserves it’s own post and one of these days I’ll actually get to it! I honestly believe it’s the only chocolate buttercream recipe you’ll ever need.
This one is made up of slightly cold butter (the temperature is key!), melted dark chocolate (good quality like Guittard or Ghirardelli is best), sifted powdered sugar (for a silky smooth finish) and heavy whipping cream (creates the light and fluffy texture). I’ve used this on many of my recipes, which you’ve probably seen, and can never get enough of it.
You’ll notice it lightens in color quite a bit as you beat it, but it will also darken after it sits out a bit.
To finish off this cake, I’ve added a chocolate drip, something I didn’t do in the original recipe. Back then I had never even attempted a drip. Now it’s one of my favorite things to add for flavor and look. The recipe below will give you enough to drizzle between layers and on top.
And because I wouldn’t want to completely erase the original post, here’s a throwback to one of the pictures I included of Westin with his cake!
The Ultimate Chocolate Cake
Dark chocolate cake layers with chocolate mousse filling, chocolate buttercream, and chocolate drip.
Prep Time 1 hr
Cook Time 20 mins
Total Time 1 hr 50 mins
FOR THE CAKE
- 2 cups (240g) all-purpose flour
- 1 3/4 cups (375 g) granulated sugar
- 3/4 cup (88.5 g) Cacao Barry Extra Brute Cocoa Powder (or similar premium brand)
- 2 teaspoons (8 g) baking soda
- 3/4 teaspoon (3 g) baking powder
- 1 teaspoon (5.6 g) salt
- 3 eggs room temperature
- 1 cup buttermilk 240 g, room temperature
- 1 cup (236.6 g) hot water or coffee
- 1/2 cup (109 g) vegetable oil
- 1 teaspoon (4.2 g) pure vanilla extract
FOR THE BUTTERCREAM
- 2 cup (452 g) unsalted butter, slightly cold
- 5 cups (625 g) powdered sugar, measured and then sifted
- 1 tablespoon (13 g) pure vanilla extract
- Pinch of salt
- 10 oz. good quality semi-sweet or dark chocolate chopped melted and cooled
- 1/4 cup (57.75 g) heavy whipping cream
- *This buttercream recipe makes enough to fill and cover your cake. If you want to add additional piping you’ll want to make an extra 1/2 batch.
FOR THE FILLING
- 3/4 cup (112.5 g) chocolate chips
- 2 1/2 cups (577.5 g) heavy cream, cold divided
- 3 tablespoons (44.3 g) cold water
- 1 tablespoon (9.25 g) unflavored gelatin
- 1/2 cup (62.5 g) powdered sugar
- 1 teaspoon (4.2 g) vanilla extract
- Pinch of salt
FOR THE DRIP
- 1 cup (150 g) dark chocolate chips
- 3/4 cup (173.25 g) heavy whipping cream
FOR THE CAKE
- Preheat the oven to 350 degrees F. Prepare three 8-inch or four 6-inch round cake pans by spraying each pan with nonstick spray, lining the bottom with parchment paper, and spraying the paper. Set aside.
- In a bowl of electric mixer, stir together all the dry ingredients. Set aside.
- Combine eggs, buttermilk, water or coffee, oil and vanilla in a measuring cup and lightly beat with a fork.
- Add wet ingredients to the dry ingredients, and mix on medium speed for two minutes. Batter will be thin. Scrape sides and mix for another 30 seconds. Divide batter evenly among prepared pans (I like to use a kitchen scale to ensure the batter is evenly distributed - should be about 16 ounces of batter in each 8-inch pan or 12 ounces for each 6-inch).
- Bake for 18-20 minutes (you may need more time depending on your oven), until toothpick comes out with just a few moist crumbs on it. Cool on wire racks for 10-15 minutes, then gently invert onto racks until cooled completely.
- When cakes are completely cooled, I like to wrap each cake layer individually with plastic wrap and stick it in the refrigerator or freezer until I’m ready to frost. The cake will be easier to work with if it’s cooled a bit. If I’m making the cake a day or two before I actually need to frost it, I put it in the freezer to ensure freshness. If I’m frosting same-day, I’ll just put it in the refrigerator to chill until needed.
FOR THE FILLING
- To make the chocolate ganache, pour 1/2 cup of the heavy cream over the chocolate chips in a microwave safe bowl. Microwave for one minute and then stir until the mixture is smooth and silky. Will be a bit thick. Let cool to room temperature but not to the point that it sets.
- In a small bowl, place the cold water and sprinkle with the gelatin. Let sit for at least 10 minutes. In a small saucepan, bring 1/3 cup heavy cream to a simmer and then stir in the gelatin mixture until it's dissolved. Refrigerate, stirring frequently, until cool but not set, about 5-7 minutes.
- In a chilled stainless steel bowl with a chilled whisk attachment, beat the remaining whipping cream, powdered sugar, vanilla and salt until it thickens and soft peaks begin to form, about one minute. Very slowly and gradually add the gelatin mixture and continue beating until medium-firm peaks form.
- Gradually fold in the cooled chocolate ganache.
- Keep covered and chilled until ready to use.
FOR THE BUTTERCREAM
- In a bowl fitted with a paddle attachment, beat the butter on medium high until light and fluffy.
- In a microwave safe bowl or over the stove, heat the cream and the chocolate. Stir to create a smooth ganache. Set aside to cool slightly.
- With the mixer on medium speed, gradually stream in the chocolate ganache. Scrape the sides of the bowl and mix again.
- With the mixer on low speed, gradually add the powdered sugar. Beat on low speed for 1 minute.
- Add vanilla and salt and beat until combined.
- Increase speed to med-high and beat for another 2-3 minutes, until light and fluffy.
- Frost cake right away, or, if you cover and use later, make sure to mix with a wooden spoon right before applying to the cake to get rid of air bubbles.
FOR THE DRIP
- In a microwave safe bowl, heat the cream.
- Pour the cream over the chocolate chips and stir the chocolate chips until they melt and they cream and chocolate is well-blended.
- Place the first cake layer on a cake board and spread about a cup of the whipped filling on top. Repeat with the second cake layer.
- Apply a thin layer of the chocolate frosting around the entire cake to lock in the crumbs. Place the cake in the freezer for 10 minutes to chill and set the crumb coat.
- Continue to frost the cake once the crumb coat is set.
- Use the chocolate drip on the cake once it's completely frosted.