Chocolate Cake with Swiss Meringue Buttercream

Learn how to make this moist chocolate cake with swiss meringue buttercream! This cake tastes like it came from a bakery yet it is so easy to achieve at home. I walk you through each step and even break down the baking science a bit to understand what makes this cake so moist! 

Happy Monday friends! I hope your weekend went well. I LOVE the weekend because I get two whole days at home spending time with Mr. BB and doing the “work” that I really want to be doing!

But then Monday arrives WAY too early. But on this Monday there is CAKE!!!!

I think Mondays feel doable when you have cake! Especially this crazy moist cake. I’m sorry if you are a person that can’t stand that word, but it is really the only way to describe this. It is out of the world, crazy moist!

When I made this recipe I really only cared about the cake as the vessel for my Swiss meringue buttercream. If you have been hanging around here the last couple of weeks, then you know I am in the middle of a series here at BB about meringue!

I made a Swiss Meringue for you on Wednesday and wanted to present to you a Swiss Meringue Buttercream today! BUT we also HAVE to talk about this cake and what makes it so moist!

I found this Moist Chocolate Cake recipe from Ina. Like I said, I didn’t plan on it being the focus of this post, but after I saw how amazing it turned out, I wanted to talk a little baking science about what makes this simple cake just so darn moist! Here is the formula below the way I adapted it for my use.

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 Moist Chocolate Cake Formula

• 1¾ cups (7.45 oz)  all purpose flour- 100%
• ¾ cup (2.25 oz) unsweetened cocoa powder- 30%
• 2 cups (14 oz) granulated white sugar- 188%
• 1½ tsp baking soda
• ¾ teaspoon salt
• 2 large (3.6 oz) eggs- 48%
• 1 cup (8 oz)  buttermilk- 107%
• ½ cup (4 oz) oil- 53%
• 1 tbsp vanilla extract
• 1 cup (8 oz) hot coffee- 107%

If you aren’t familiar with using Baker’s Percentages, these numbers are probably looking a little weird to you. I wrote a post a while back going into depth about baker’s percentages, how to calculate them, and why they are useful.

But really the only thing you need to understand here is that the amount of flour is always set at 100% and then the percentage of every other ingredient is calculated off that based on the weight of the flour compared to the weight of the other ingredient.

When looking at these numbers for this cake I immediately notice that the sugar ratio is very high. We have discussed before about how sugar is hygroscopic, meaning it holds onto moisture. Because of this, high sugar cakes tend to be a more moist cake.

You will also notice that with the combination of the buttermilk and coffee we are looking at more than double the amount of liquid to flour by weight. For obvious reasons, this will also contribute to this cake being super moist!

You may also notice that this cake only calls for baking soda and not baking powder. Both buttermilk and coffee are acidic so these ingredients will get that baking soda activated and working to leaven the cake.

For this reason, it also does not matter in this particular cake like it does in other baked goods if you use natural cocoa powder or dutch processed. Either will work, but dutch processed will give a darker color and richer chocolate flavor to your cake.

This cake is actually super simple to put together. I’ll walk you through it.

Step 1- Place all of the dry ingredients into your mixing bowl. Mix all of the dry ingredients (flour, cocoa powder, sugar, baking soda, salt) together.

Step 2- Add in the wet ingredients, minus the hot coffee. Mix together the eggs, buttermilk, oil, and vanilla and mix into the dry ingredients just until incorporated. I quickly whisked all of the wet ingredients together in a large liquid measuring cup and then poured them in with the mixer on low. Scrape down the bowl.

Step 3- Mix in the hot coffee. With the mixer still running, pour in the hot coffee. This is going to make your batter super liquidy and you are probably thinking that there is no way it is going to set. It will! Pinky promise. Also, if you don’t like coffee not to worry. This cake in no way tastes like coffee. The coffee just intensifies the chocolate flavor and also adds more moisture to the cake.

Step 4- Pan and bake. Pour the batter evenly between two prepared cake pans. (I know, I know! I need to get some real cake pans and stop using disposable tins! I do have one set of real ones, but when I need two of the same size, I’m out of luck!) . Bake at 350F for 30-35 minutes.

Step 5- Let them cool! Once those babies are done, let them cool for at least 20 minutes before depanning them.

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Now, moving on to that Chocolate Swiss Meringue Buttercream!

I gave you a detailed tutorial of how to make the Swiss Meringue last week, but I will quickly recap so we can get into the buttercream.

Swiss Meringue Buttercream

Swiss meringue buttercream is simply Swiss meringue that has butter beaten into it. It’s literally that simple. It is incredibly smooth and light, it pipes well, and is great for getting those super smooth cakes if you are good at that kinda thing, which I am not, so ignore that part.

If you need a more detailed tutorial on making Swiss Meringue, please see my Swiss Meringue 101 post! 

Step 1- Prep the butter. About 30 minutes before making your buttercream, remove the butter from the refrigerator and cut it into chunks, about 1 TBSP each. You want the butter to soften slightly, but you don’t want it to be warm.

Step 2- Heat the Egg Whites and Sugar over a double boiler. Place your egg whites and sugar in a heat proof mixing bowl and set over a double boiler. Whisk and warm over the double boiler until the mixture reaches 160F. This mixture will be liquidy and smooth with all of the sugar melted.

Step 3- Whip the mixture. Whip the warm egg white/sugar mixture on high with the whisk attachment of your stand mixer until cooled and then continue until stiff peaks are reached.

Step 4- Beat the butter into the meringue. With the mixer on medium-high speed, add 1 chunk of butter a time. Let the piece incorporate into the meringue before adding the next one. At this point you mixture will most likely start looking curdled like cottage cheese. Don’t freak out! It will start going there, get worse, and then if you keep mixing it will smooth out and whip up!

Step 4- Mix on high until you have a silky smooth frosting. At this point, you have regular swiss meringue buttercream. You can add in some vanilla or keep as is.

But I added chocolate! 

And folded it in until I had this luscious chocolate swiss meringue buttercream!

And I have to say, as a frosting hater, I liked this frosting! I was good with not having to push it off my cake. I liked it because it is not overly sweet and it has more of a real buttery flavor. It also stays super light and just isn’t heavy like a lot of frostings.

Then you just assemble you cake, frost, and serve! Don’t ask me for tips yet on frosting! I’m terrible at it but it is one of my goals I’m working on this year. Step 1, get a turn table! I like this video tutorial for how to smooth swiss meringue buttercream.

I hope you are enjoying this series on meringues. I would love to hear any requests from you for my next series. I have been talking about doing one an cooking eggs for a while now so maybe that should be next up!

I hope you Monday goes well! Just have some cake! It helps!

One year ago: Sharp Cheddar and Thyme Cheese Puffs

Two years ago: Easy No-Knead Skillet Bread

Three years ago: Homemade Marshmallows and Sweet Ideas to Decorate for Valentine’s Day