Filed under: Cakes / Layer cakes
August 1, 2021

Black Cocoa Cake

This is one very special cake: it looks like the richest cake but it’s not overly sweet. Black cocoa adds smoky, earthy notes, and full fat kefir makes the cake incredibly tender and balanced. It’s dramatic to look at and delightful to eat.

Yield: 12
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Rich chocolate cake that’s not overly sweet. Black cocoa adds smoky, earthy notes to this wonderfully tender layer cake. 

 

black cocoa cake

The darkest cake, ever. 

A long, long time ago (ok, it was like two years but a lot has happened since) I made a chocolate cake with a chocolate mascarpone buttercream and used some black cocoa in it. I remember thinking the cake was lovely in person and I tried taking photos of it but felt they were just meh but the cake was gone and I had no other content one evening, so I posted it.  It soared past anything I had done before then on IG (it continues to get a lot of attention on Pinterest) and it was all because of the color: it was black. 

When I reposted it, I got a slew of messages asking for the cake recipe (not just the buttercream) which wasn’t mine. And it’s always bothered me that: a. The cake didn’t use black cocoa like the buttercream and b. The cake recipe wasn’t one of my own creations. It’s not like I don’t have a go-to chocolate cake recipe which I love even more than that one, I just hadn’t used it that particular day. 

So it’s time to set this right with my own recipe for a cake that is 100% made with black cocoa. And because black cocoa is devoid of fat (more on that in a bit) full fat kefir/buttermilk ensures the cake is still ultra-tender, the way all cakes should be. 

 

What is black cocoa and why make a black cocoa cake? 

You are likely more familiar with black cocoa than you think; it’s the cocoa that’s used to make your favorite chocolate sandwich cookies: oreos! It’s a rare and special kind of cocoa because of the drama it adds to any baked good; turns it completely black. Truly,the color is wonderful but black cocoa is so much more than it’s color! 

It’s earthy, smokey and tastes different than other cocoas. Because it’s ‘double dutched’ (alkalized) it’s got some almost bitter notes to it. When you use it in baking it really balances out the sweetness coming from the sugar (which in turn, is necessary for texture and structure and why I always ask you not to reduce it). 

 

Kefir and buttermilk for Black Cocoa Cake

By now you know how much I love using buttermilk in my recipes, it makes the bake taste tangy and less one-dimensional but more than that it is responsible for a tender cake. Kefir, like buttermilk, is also a cultured milk, but where buttermilk is fermented with just lactic acid bacteria, kefir is fermented with several kefir grains (colonies of bacteria). They taste fairly similar and their consistency is similar as well. 

While I’ve used it for years to make things like pancakes and waffles for the girl’s breakfast (it’s a great way to get them those healthy probiotics), I have begun using kefir frequently in place of buttermilk lately for a few reasons: 

  • I can find it in full fat more frequently, whereas I only find low fat buttermilk in my area.
  • It lasts longer than buttermilk; a few months compared to a few weeks. 
  • It is tangier and creamier; so everything I love about buttermilk and more! 

 

In this cake specifically I use full fat kefir because of the lack of fat from the black cocoa. The tangy taste also pairs nicely with the muted sweetness of black cocoa. 

 

black cocoa buttercream

Ingredient info and substitutions for black cocoa cake

  • Cake or all purpose flour: for a more tender and soft cake you can use cake flour, however it will be a little harder to frost (you can freeze it for a bit before you frost to make it easier). 
  • Black cocoa: If you cannot find it and still crave a rich chocolate cake, this can be turned into a dark chocolate cake simply by using dutch process cocoa. 
  • Kefir: the acidity of kefir balances the ph out in the cake and the fat compensates for the lack of fat in black cocoa. If you cannot find kefir, you can use full fat buttermilk or thinned out full fat greek yogurt. In a pinch you can use low-fat.
  • Chocolate: I add melted chocolate to the buttercream to give it a richer chocolate taste but also to smooth it out. Since the cake itself is not very sweet I used a semi-sweet chocolate (55% cocoa solids) but you can use what you like. 

 

Tips for frosting black cocoa cake 

  • Make the buttercream ahead of time and let it sit at room temperature 
  • The cooler the cakes are, the easier they will be to frost. I set mine in the freezer for about an hour before I frost. 
  • Buttercream temperature matters: if the buttercream is cold it won’t spread or pipe nicely, if it’s too warm it will make a mess. If you make it early, keep it refrigerated until an hour or two before you are going to use it. 

Recipe for Black Cocoa Cake 

Black Cocoa Cake

Rich, moist & fluffy chocolate cake made with black cocoa. Covered in a black cocoa buttercream.
black cocoa cake
Prep Time: 30 mins
Cook Time: 30 mins
Yields: 12
5 from 12 votes

Ingredients

Black Cocoa Cake Ingredients

  • 1 cup unsalted butter at room temperature (226g)
  • 2 cups granulated sugar 420g
  • 1 tablespoon pure vanilla extract
  • 1 teaspoon fine sea salt
  • 4 large eggs
  • 2 ½ cups cake flour 325g
  • 1 cup black cocoa 85g
  • 1 teaspoon baking soda
  • 1 ½ cups full-fat kefir or buttermilk 350g

Black Cocoa Buttercream Ingredients

  • 1 ½ cups unsalted butter at room temperature (3 sticks, or 330g)
  • cup black cocoa 28g
  • 3 ½ cups organic powdered sugar sifted (455g)
  • 1 tablespoon vanilla
  • ½ tsp fine sea salt
  • 113 g semi-sweet chocolate optional

Method

How to make black cocoa buttercream

  • Beat the butter with the vanilla and salt for 1 minute. Add the cocoa and powdered sugar and beat it until smooth. If adding the chocolate, heat it in the microwave until mostly melted then stir until smooth. Once it’s cool, stir it into the buttercream. If not using the chocolate, add milk or heavy cream until the buttercream is smooth (about 2-3 tablespoons). Set aside, in an airtight container or covered with plastic wrap.

How to make black cocoa cake

  • Preheat the oven to 325. Grease and flour two tall 8” or 9″ round cake pans.
  • Beat together the butter, sugar, vanilla and salt until light and fluffy, about 4-5 minutes.
  • Add the eggs, one by one, allowing each to beat fully before adding another. Once all the eggs are in, beat for another 2 full minutes.
  • Sift in the cocoa, baking soda and flour and with the mixer on, pour the kefir in and mix until the batter is fully incorporated (scrape the bottom a few times to make sure nothing got stuck and didn’t blend). Avoid overbeating this once the flour is in the batter or the cake will come out tough.
  • Bake the cakes for 40-45 minutes, until a cake tester turns out clean or you can press the surface of the center of the cake and it springs back.
  • Let the cakes cool in the pan for 5-10 minutes, then flip them onto a wire rack to fully cool. Transfer to the freezer, wrapped tightly in plastic wrap, for an hour or more.
  • Frost the cakes when they are cold.

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Recipe Rating




  1. 5 stars
    Chocolate cakes can often be dry, but this one was beyond delicious and moist. The depth of flavor is fantastic. This has become my go to chocolate cake recipe

  2. 5 stars
    I made this a while back, and it came out so well! So beautifully earthy and luscious. I did, however, use oil instead of butter. Mine turned out well, but I highly suggest that you follow Sam’s recipe before you embark on your own experiment.

  3. 5 stars
    This cake was so yummy! Had a great black color and texture was very good. I baked it as a sheet cake in a metal 13×9 pan. Was good to take out of the oven after 45 min. I made the full batch of frosting but had leftovers. I would reduce the frosting amount by a quarter or third if I did a sheet cake again. I also used black cocoa powder from Modern Mountain since it was what I could easily get on Amazon.

    My only possible change for next time would be to add more cocoa powder to the buttercream. It was good but I wish the chocolate flavor was a bit stronger. I didn’t use the semi sweet chocolate in mine so that could have been why.

  4. 5 stars
    This recipe needs 10 stars. Easy to follow, and it’s definitely one of the top 3 best tasting cakes I’ve ever had. Thank you so much Sam for sharing!

    • 5 stars
      I ended up making this recipe as 4 layers with 6 inch pans (I made two smaller cakes). I used buttermilk and King Arthur’s black cocoa in my recipe. The bake times were about the same, I think I left them in for a few minutes longer. The cakes were wonderfully moist and I received so many nice comments from my husband and colleagues who devoured it. I also loved the fact that it wasn’t overly sweet. I personally liked this cake even better than traditional chocolate cake. So happy I came across your Instagram page and recipes. Will definitely be my go-to chocolate cake!

  5. I’m baking right now but they are overflowing in the oven. I was careful with the ingredients , etc and I used 8 inch pans…..

    • Oh no Dina!!! This is so frustrating. I think this might be an issue of the pans being too shallow. When you add the batter to the pans it there should be enough room for the cakes to almost double in size. Hopefully you can catch the extra batter and the cakes will still turn out ok?

  6. 5 stars
    I made this for my sisters 50th and it was amazing! I followed the recipe exactly. Did three cake layers instead of two and added a teaspoon of instant espresso powder in the frosting. It was divine! My husband (who does not prefer chocolate) ate 3 pieces.

  7. 5 stars
    What an excellent chocolate cake! This is my first time using black cocoa and wow does it add lovely chocolate notes to this cake. I paired the cake with your chocolate mascarpone buttercream and it was excellent! Certainly something you could order at a fancy restaurant. Thank you for the recipe!

  8. Very excited to try this cake for an “Oreo” alternative. I’ve previously made your initial black cocoa cake by substituting a portion of the cocoa for black cocoa – it was perfection! Hoping to try this for 2 9” pans, suggestions on proportions?

    • Hi Dema! I don’t have another black cocoa cake 😐 (unless you meant the KAF cake with the mascarpone buttercream…). But yes two 9″ pans will be fine, the layers will be a bit thinner and will bake quicker so I”d check it 10 mins early.

  9. Hello, I tried both recipes the black cocoa one and the blueberry… I put them in the freezer before frosting overnight and the cakes were so very dry…the frostings were amazing… so was it the freezing part that caused them both to be dry?

    • Hi Rose! SO sorry they were so dry =( If you froze them completely covered (plastic wrap and in an airtight container) then I don’t think it was the freezer. Could it be that the flour was overmeasured or that the type of flour was a higher protein content?

  10. 5 stars
    This is the first black cocoa cake recipe I’ve made that wasn’t a crumbly mess. The flavor and texture are perfect! I substituted 1/3 of the butter with oil and it seemed to help the cake to stay moist. The butter definitely helps with the cake’s structure.

  11. Would using vegetable oil keep it moist? If I were to sub would I sub 1 for 1 with butter? I don’t typically sub on recipes but I am very into moist leftover cake LOL

    • Hi Lily, a few people have told me they’ve done it successfully but I haven’t myself. I think if you are using cake flour, measuring everything carefully you won’t have to worry too much about it going dry

  12. Hi- should the eggs be room temp or cold? I’m waiting for my cakes to cool now and color is great but they sank in the middle. My butter may have been too soft, but I also wonder about the egg temp. Thank you!

    • Hi Nancy, I’m so sorry they sank! The eggs ideally would be room temp but it wouldn’t have caused the cakes to sink. Usually cakes sink when there’s an issue with the leavening (here baking soda)/if they were overmixed or if the oven door was opened during baking.

  13. 5 stars
    Recipe is delicious! I bundt’ed it. No change to ingredients or amounts. Almost 50 minute bake time. And I halved the icing.

    • You would thin it out until it’s the consistency of a thick buttermilk or kefir. I’d do 1 cup greek yogurt and 1/2 cup water but add more or less depending on how it changes.

  14. Does the buttercream in these photos have the optional semi-sweet chocolate? I used it and my frosting is much lighter in color. I prefer the visual of black on black and may try leaving it out next time if that is what contributes to your extra dark frosting. The cake was delectable!!

  15. Should the butter be room temp before beating for the cake? Also – planning to make a week in advance and will freeze until needing to frost. I know you said this cake dries out fast – will the freezing prevent the dry out?

  16. Can’t wait to try this recipe! May I ask, why using butter instead of oil? I know a lot of chocolate cakes recipes use oil. From the pictures it looks very tender so I’m guessing it’s to get that texture??

    • Hi Ana, it’s a good question and something I’ve been thinking about actually. The short answer is I began testing this cake based off a recipe that was in one of the cookbooks my mom had when I was a kid (can’t remember the name – it was a little thin thing she got in the grocery store, very forgettable) and that one had butter. I have been thinking about trying to do another oil-based version because this one does dry out in the days after baking. We’ll see!

      • 5 stars
        Made this cake for my birthday. Everyone loved it! It had such a depth of flavor. Thank you for the recipe. It was the best part of my birthday.

    • I think it could all fit in there, it would be a taller 13×9. Bake temp can stay the same but you’ll judge doneness by checking the cake itself (press the top to see if it springs back or use a cake tester). I’d check it first at 25 minutes and go from there