I decided to combine a slight adaptation of Amy Sedaris's Rich Chocolate Cake, my go-to chocolate cake and cupcake recipe, with a coffee buttercream recipe I found from Martha Stewart's website. If you haven't read Amy's first book, I like you, you should go find a copy STAT. It's hilarious (the Rich Chocolate Cake is in a chapter about entertaining a rich uncle that also includes Silver Dollar Pancakes) and the recipes are actually really good! The cocoa whipped cream topping that accompanies the cake in the book is also delicious, but not the best for a traveling cake. This one has to make it 15+ miles tomorrow!
OK, so the cake: Preheat the oven to 350.
I usually line the bottom of the pan with waxed paper or parchment, too, but as it turns out, I'm out of both. Oops!
Mix 3/4 cup unsweetened cocoa powder, 3/4 cup boiling water, and 1 c buttermilk in a bowl. Stir well and set aside.
This step is what makes this recipe so good. Bland chocolate cake makes me sad. Some good recipes add the cocoa to hot water to "bloom" the flavor, and others add buttermilk for the same reason. This one has both, and it makes all the difference! It makes the cake super chocolatey without making it fudgy. Fudgy is good sometimes, but I like it like this, too.
I bought these Pyrex liquid measures in college and was chided by a friend for buying something expensive "like your mom has". Twenty-some years later, I'm glad I splurged on them!
Another secret weapon in chocolate cake baking: instant espresso powder. Add 1 tsp to the cocoa mixture.
In another medium bowl, mix 2 1/2 c flour (white or a mix of white and whole wheat), 1 1/2 tsp baking powder, 1/2 tsp baking soda, and 1 tsp salt.
You need salt in sweet stuff to bring balance and highlight the flavors. It's why we're all in love with salted caramel right now!
Cream (on medium speed) 1 1/2 sticks unsalted butter and 1 3/4 c granulated or raw sugar until fluffy.
It's best if the butter is softened to close to room temp, but if you forget it's ok, just beat it longer. Do take the butter out for the buttercream now, if you've forgotten. It's more important that that butter be soft.
Add 4 eggs, one at a time, stopping to scrape down the bowl between additions. Beat for another minute after the last one, then add 2 tsp vanilla extract.
Scrape down the sides and scrape up the bottom of the bowl, then add 1/3 of the flour mix, beating just to incorporate, and 1/3 of the cocoa mix, again beating just to incorporate. Scrape down the sides and repeat with the remaining thirds of the bowls.
Pour the batter into the prepared pans and put them in the oven. Put them on the same shelf if possible, making sure they're not touching each other or the sides of the oven.
Bake for about 25 min, until a toothpick comes out clean and the cake comes away from the sides.
Start checking after 20 minutes, though, and if they're not the same amount of "done", switch the positions of the pans.
Remove the pans from the oven when they pass the toothpick test and let cool in the pans for 10 minutes.
Place a plate on top of the pan and flip the cake onto it, then place a cooling rack on top of the cake and invert it so the top is up. Let cool completely before making the frosting or buttercream.
You could absolutely do an American Buttercream for this, aka the good old powdered sugar frosting recipe on the back of the box.
To start a different kind of buttercream, make sure your 3 sticks of butter are nice and soft. Cut it into small pieces.
Dissolve 1 Tbsp plus 1 tsp espresso powder in 2 Tbsp hot water. Set aside.
Add 4 egg whites and 1 1/4 sugar to a large heatproof bowl, ideally the bowl of a stand mixer. Set the bowl over simmering water and whisk until the sugar is dissolved and mixture is hot to the touch.
With the whisk attachment of a stand mixer, or a plain old cheapy hand mixer, whatever you've got, start beating the egg white mixture on low and gradually change to high speed.
Beat until the egg whites are glossy and stand in stiff peaks when you left the beaters, about 8-10 minutes.
Beat in the butter pieces until smooth, then pour in the coffee mixture and beat until combined with no streaks. Turn off and scrape down the sides, then start again if it comes up like this.
Put the first layer on the plate you'll use for serving. Trim the top a little to help the layers stack nicely: place a long serrated knife at the edge of the dome-y part and hold it there while you turn the plate in a circle. Remove that little piece and eat it - you gotta do some quality control, am I right?
Use a long spatula or a butter knife to put a big glob of buttercream on the middle of the cake. Spread to the edges from the middle, adding more if you need to.
Repeat with the second layer.
Refrigerate the cake until it's almost time to serve.
If you're taking the cake somewhere, chill before you go and use a bamboo skewer or two to make sure the layers stay put!