The Ultimate Chocolate Cake – dark chocolate cake layers with chocolate mousse filling, chocolate buttercream, and chocolate drip.
Recipe Revisit
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.
Chocolate Cake
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.
Chocolate Mousse
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.
Chocolate Buttercream
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.
Chocolate Drip
Chocolate DripTo 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.
Throwback
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!
Enjoy!
The Ultimate Chocolate Cake
Ingredients
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 (6 g) salt
- 3 eggs, room temperature
- 1 cup (240 g) buttermilk, 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 ½ 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 (180 g) dark chocolate chips
- 3/4 cup (173.25 g) heavy whipping cream
Instructions
FOR THE CAKE
- Preheat the oven to 325 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 25 to 30 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 ½ 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 ⅓ 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.
ASSEMBLY
- 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.
Does this cake need to be refrigerated?
It can be on the counter, in a container of some kind, for a few hours. If you’re going to wait longer than that to eat it, you can refrigerate it. I just won’t like to use the fridge for too long. It can dry things out. Freezing it works great too.
Hi Courtney,
The cakes came out very thin, i am not sure what i did wrong. Do you have any idea?
Thank you.
Hmmm, what size pans did you use? And is your baking powder and baking soda fresh (purchased within the last 6 months)? Also, it’s good to make sure the temperature of your oven is accurate with an internal oven thermometer. If the oven is off by a few degrees or more, it will affect how the cake bakes.
My cakes were way thin too. I bought new baking powder and baking soda for this cake. Comparing to other recipes, these proportions are usually baked into 2 cakes, not 3. Is that the issue?
The chocolate cake layers are a little thinner than vanilla layers but they should still be a good size. The recipe is for a 3 layer cake.
Does freezing this cake effect the mousse filling at all?
Hi Courtney, I have been following your blog and would like to try this Chocolate Cake recipe. However, we don’t usually use cups measurement, is there any way I can convert it to grams?
Thank you so much
Yes, google has some great converters
You have a very nice blog and your photos are beautiful. This recipe looks really good and I may try it, but I do have a wee tiny criticism. It’s not meant to be snarky, but a way that I think would improve your recipes and website. Here goes. Most pro and avid bakers use weight measurements in their recipes. Why? Because it’s more accurate and alleviates the fiddly process of measuring out a cup of flour and then subtracting 2 tablespoons from it. OYE, who has time for all that adding and subtracting, not to mention 3 people scooping flour and subtracting small amounts will each end up with a different amount of that ingredient. It’s so much simpler, even if you use Imperial measurements (ounces) rather than metric (grams). It really looks like a good recipe, but can you please either convert to weight or at least add the weight into the ingredient list so we can all make this delicious looking cake with the easiest and most accurate method. I hope you can see that I’m trying to help, not hinder your blogging and sharing of recipes. ♥
What are the chocolate pearls on top?
Those are from Orson Gygi
I’m so excited you just posted this — I need to make a cake for my little boys birthday tomorrow and even though I have my tried and true chocolate, I’m going to try this one because it just sounds exciting 😆 have you ever used a cup of brewed crio bru instead of the water/coffee? I’m thinking it won’t hurt right? It’s pretty bitter, but isn’t coffee bitter too?
I haven’t but it would be amazing as a flavor enhancer. I love crio bru
If I was just going to use frosting in between the layers instead of mousse, would you say make 1.5 of the frosting or 2x?
Just an extra half
What are the chocolate balls you’ve used for decoration?
Made this cake for my husband for fathers day, slightly after fathers day. it was a hit! So good! Love the chocolate filling and the buttercream frosting was perfection! Defiantly the ultimate chocolate cake. Good thing I have a bunch of chocolate lovers in my family.
Ok I made this with the crio bru (1.5 T grounds) and it was so so good! Like I’m obsessed with the cake itself, and will double the grounds the next time I make it because I think it’ll be even better! My only tip to those making it is start whipping your cream *while* the gelatin cream is cooling, and maybe don’t put it in the fridge unless necessary. I started whipping my cream (but with a handheld device not my kitchen aid because I’m at a lake cabin) and my gelatin cream was in the fridge cooking but by the time I got soft peaks it was totally gelatinized. I heated it up again a little to liquify it but still ended up with little clumps throughout the whole filling. Still delicious and not noticeable to others but noticeable to me. Otherwise, so delicious! And the best chocolate buttercream I’ve ever made as well. I will definitely be trying more of your recipes! And Courtney if you read down this far I am wondering if I want to keep my cake in the fridge and serve it cool can I add more heavy whip to my buttercream so it doesn’t harden up so much?
What would be the timing/ amounts if you use 6inch rounds instead? Thanks, this cake looks so yummy!
It will be about the same time! Use a food scale to get equal amounts of batter in each pan.
Recipe looks great and I’m going to try it. Wondering how far ahead I can make the whipped chocolate filling?
A week is ok. Just covered and refrigerated.
Hello,
I made this cake last night. The cake itself was wonderful; however, I ran into trouble with the whipped filling. It says to use 2 1/2 cups of heavy whipping cream divided. You use 1/2 a cup for the ganache and then 1/3 cup for the gelatin mixture and the remainder goes in the stainless steel bowl. Which would be 1 2/3 cup of remaining heavy whipping cream. Once I added the remaining whipping cream, it was super runny. I thought that maybe I messed up the amount of remaining heavy whipping cream or maybe it needed more powdered sugar than the 1/2 C it called for. It never formed peaks. I went against my gut and added the gelatin mixture anyways and it was just a hot mess. I was super disappointed it didn’t turn out. I ended up adding a ton of powdered sugar to the final whipped filling just so i could still use it. At least it tasted good though. Do you have any idea what I did? I’d love to hear your thoughts. Thanks!
How long did you whip the remaining whipping cream? It helps to use a chilled bowl.
Was just making this – very excited to take a bite! But I think the recipe might be off for the chocolate drip. It says 1 c chips to 1 c cream and I just made, not really thinking, and it is way too much cream. I checked another drip recipe and saw it was 1 c chips to 1/2 c cream. Just wanted to suggest the change in case someone else (like me) makes it without thinking!
The drip is definitely thinner than the ganache (which is the 1c chips to 1/2 cup cream). The one to one ratio is good for dark chocolate and will thicken as it sits out for about 10 to 15 minutes.
Question: the ganache drip in this recipe called for a cup of cream. It was more than some of the other drip recipes. I had to add chocolate to thicken it up. Was this a type-o it said 1 cup of cream /1 cup of chocolate chips.
Question: the ganache drip in this recipe called for a cup of cream. It was more than some of the other drip recipes. I had to add chocolate to thicken it up. Was this a type-o it said 1 cup of cream /1 cup of chocolate chips. But the cake and flavor was great! Chocolate overload.
Thanks! Yeah I think 1 cup is too much for some chocolates. Depends on the brand. But 3/4 cup cream is the way to go.
Is this similar to a devil’s food cake?
Similair!
Can we sub the flour in this cake recipe for gluten free flour 1 to 1?
Yes!
Is this similar to a devils food cake?
Do you think this cake recipe would lend itself to petit fours? I’m thinking a 12×17″ pan, but do you think it will hold up when slicked into two layers? Thanks for your help and your wonderful website!
You should bake it in a half sheet pan. Then you can cut out the petit fours and double stack them.