Dark chocolate cake that is surprisingly moist and sturdy (i.e. stackable), with an Oreo cookie chocolate taste. This cake is rich in chocolate flavor yet lightly sweet to create the perfect balance that will only leave you wanting more.

The story

I found out I was making a blackout cake for the first time about two minutes before the black cocoa needed to go in. I’m a big believer in mise en place (everything out and ready before you begin), so I even had regular cocoa on the counter. I’d started measuring dry ingredients for my husband’s birthday cake when he walked in, opened an Amazon box that had just arrived, and handed me black dutched cocoa.

Oh, so we’re doing that? Good to know.

I’d heard of black cocoa before, from Chelsweets, who uses it to help dye cakes black naturally. I mean, the black teeth and tongue look is pretty cool, but it’s not for everyone. We accidentally stained everyone’s tongue and teeth at our engagement party. As fun as it was to take some photos with us sticking our black tongues out (I’ll spare you, it’s not pretty), it wasn’t fun trying to get a real photo and hide our teeth at the same time.

What I didn’t realize is that black cocoa has a distinctly different taste. It tastes like Oreos. For me, this was life-changing. I don’t know how I’ll ever make a normal chocolate cake again.

I based this cake on my chocolate Charity cake, with a few changes.

I added an extra egg. I started doing this recently, in an attempt to add sturdiness to my cakes without drying them out.
I adjusted the ratio of wet and dry ingredients. This was mostly to accommodate for the extra egg. Also, I knew I wasn’t going to use the extra 2 tablespoons of cocoa that I usually add, so I knew I needed more flour to make up for it.
I used less sugar. When I make my chocolate cake, I often use less sugar than it calls for. It’s mostly for health, but also because I like the extra rich flavor it creates. So of course I was going to use less for my husband’s birthday, since he’s the one who started the trend. Wow did it work well in this recipe. I honestly don’t think I’d like it if it were any sweeter.
I used light coffee. So far, I’ve only used Starbucks blond roast. Because it’s a 3 minute walk from my house and I only have espresso on hand. But I wanted to see what would happen using light coffee. It was amazing. I’ve had similar results with my espresso back of making an Americano—one double shot then hot water to make 1 cup total. But I think the lighter roast also made a difference. So, if all you have is dark roast, make a slightly weaker coffee than usual to compensate.

These changes created a very moist, slightly rich (but not too much), very sturdy cake. In fact, I used a terribly unstable combination of Nutella and marshmallow fluff for the filling. The real problem was that I used both in each layer and the filling was too thick for something so ice-cream-topping-ish. There was some sliding, but the cake still held up well.

Oh, and I got compliments from people who don’t even like cake.

Tips for this recipe

Use light roast coffee

If you don’t want to buy light roast beans, you can easily stop at a coffee shop (I encourage supporting local business these days!). Just have your ingredients measured out up until the point of adding the coffee (so dry is sifted and whisked, wet minus coffee are in a bowl warming up), then go grab blond roast coffee. Grab one for yourself, too. You deserve it.

Or, you can buy it before you start and put it in a small saucepan on the lowest possible setting until you need it. It’ll keep it warm but not burn it. Just remember you need 8 ounces for a regular recipe, more if you’re increasing it. Most coffee shops leave a little room, so get more than an 8 ounce cup.

Use a stand mixer or hand mixer

Unfortunately, I’ve never had good luck making this cake without a stand or hand mixer. The two minutes on medium really make a difference—any less and you get a flat, dense cake. The paddle attachment provides the perfect amount of mixing and aeration. A hand mixer will work, too, but you need to mix it for only one minute. Whisking by hand is trickier, because there’s no way to regulate the speed. Usually, it causes over mixing and a dense, chewy cake, which is why I don’t recommend it.

You can honestly cool it in the pans

Generally, bakers subscribe to the best practice of cooking for a few minutes in the pan just to set the cake then removing to a cooking rack to prevent it baking further on the counter. I only do this if I left my cake in a little longer than I meant to. Otherwise, I tend to just leave them in the pans until I’m ready to frost. But, this does mean it takes longer for them to cool. I’m rarely on top of my game and value the extra time to make my frosting. 😳

Check more than just the middle for doneness

The first time I made this cake, the middle was cooked, the edges were cooked, but halfway between the two wasn’t. You can see it in the photo above—that ring where it cracked. Weirdly, it fell in that spot as it began to cool. Luckily, I was able to fix this by putting them back in the oven for a few minutes. Lesson learned—check more than just the middle and check each cake individually, as one might finish faster.

Pair with any frosting!

Because this cake requires so little sugar, you can use a sweeter filling/frosting if you want, like my Nutella frosting (pictured below), white chocolate buttercream, or marshmallow buttercream (especially if you like cookies and cream!). Or, if you don’t like super sweet cakes, use something light like whipped cream filling, raspberry filling (using less or no sugar), or Swiss or Italian meringue buttercream (if you’re brave—I’m not). Plain vanilla buttercream using clear vanilla will make for the ultimate black and white cake. Or, for ultra chocolate on chocolate that’s rich and just a touch sweet, use my ganache buttercream.

Dark Chocolate Blackout Cake

prep time: 10 minutes

cook time: 30 minutes

total time: 40 minutes

Servings: 12-16

Ingredients:

1 to 1 ¼ cups sugar

1 ¾ cups flour, sifted

¾ cup black dutched cocoa, sifted

2 teaspoons baking powder, sifted

1 slightly rounded teaspoon baking soda, sifted

½ teaspoon fine ground Himalayan sea salt (or 1 teaspoon table salt, but sea salt gives a better flavor)

3 large eggs, room temperature

8 ounces buttermilk, room temperature (leave out about 30 min)

⅓ cup avocado or olive oil (can sub grapeseed or vegetable oil)

1 tablespoon pure vanilla extract

1 cup hot blond/light roast coffee

Instructions:

Preheat oven to 325*. Grease and flour two 8" or 9" round cake pans (or use baking spray). Line bottoms with parchment paper.

In the bowl of stand mixer (or large mixing bowl), add sugar then set fine mesh sieve over the bowl to add/sift flour, black cocoa, baking powder,baking soda, and salt. Whisk by hand until fully combined (you can tell because the cocoa color has evenly spread).

In a separate bowl, whisk together eggs, buttermilk, oil, and vanilla. VERY slowly, begin to pour in the hot coffee, whisking quickly and constantly to avoid scrambled eggs. Feel free to do it in increments if this is your first time.

Using the paddle attachment of your stand mixer (or a hand mixer), slowly pour wet ingredients into dry with the mixer on low. It will clump up halfway through then settle into a liquidy consistency. After all ingredients are combined, scrape down sides and bottom. Turn mixer up to medium and mix for 2 minutes. Set a timer so you don’t overmix.

Pour batter evenly into prepared pans. I highly recommend using Wilton Bake Even Strips to avoid a domed cake (or you can cut this off with a large, serrated knife and have a little pre-cake snack).

Bake for 25-35 minutes until a toothpick inserted in the middle and halfway between middle and edge comes out clean or with moist crumbs. Check bake halfway through to be sure they’re not baking too quickly—climate can impact bake time. If not using a convection oven, rotate cakes at this point as well. Check again every 5 minutes to avoid overbaking.

Cool in pans 5-10 minutes then remove to a cooling rack until completely cooled.

Frost and enjoy!

Cake will last covered at room temperature 3-5 days, unless frosting/filling needs refrigeration. If not frosting right away, wrap tightly in plastic wrap and leave at room temperature overnight or freeze up to 2 weeks.