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mocha cake with bird's nest
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Mocha Cake

A rich and delicious cake flavored with dark chocolate and coffee, and layered and topped by a silky mocha Swiss meringue buttercream.
Prep Time 30 minutes
Cook Time 40 minutes
Total Time 1 hour 10 minutes
Servings 12
Author Jen Leigh

Ingredients

For the cake:

  • 3/4 cup cocoa powder, sifted, plus more for dusting
  • 2 1/4 cup flour
  • 3/4 tsp baking powder
  • 1 tsp baking soda
  • 3 eggs
  • 3/4 cup butter
  • 1 3/4 cups sugar
  • 1 1/2 tsp vanilla
  • 3/4 cup buttermilk
  • 1 cup strong, freshly brewed hot coffee
  • 1 tsp fine sea salt

Mocha Swiss Meringue Buttercream:

  • 6 large egg whites
  • 2 cups granulated sugar
  • 2 cups unsalted butter, room temperature, cubed
  • 1/4 tsp kosher salt
  • 1 tsp vanilla
  • 1 1/2 tbsp espresso powder*
  • 5 oz bittersweet chocolate chopped, melted and cooled

Instructions

Cake:

  • Pre-heat oven to 350°F.
  • Grease three 6-inch round cake pans and dust with cocoa powder. Line the bottoms of the pans with parchment rounds and set aside.
  • In a large bowl, sift together the flour, cocoa powder, baking powder, baking soda and salt. Set aside.
  • Combine the butter and sugar in the bowl of a mixer and beat together. 
  • With the mixer going, add one egg at a time to the bowl.
  • When all the eggs have been incorporated, scrape down the bowl and add the vanilla. Mix briefly to combine.
  • Add the dry ingredients slowly in three batches, mixing to combine, until incorporated. The batter should be very thick.
  • Slowly add the buttermilk, and then the coffee, mixing on medium-low until incorporated and the batter is thinner.
  • Pour the batter evenly into the three greased cake pans. 
  • Bake for 30-35 minutes or until a toothpick inserted in the center comes out mostly clean. 
  • Remove from the oven and let cool for at least 10 minutes in the pans, then transfer to cooling racks. 

Mocha Swiss Meringue Buttercream:

  • Place egg whites and sugar into the bowl of a stand mixer, and whisk until combined.
  • Set mixer bowl over a saucepan filled with 1 inch of gently simmering water, making sure bottom of the bowl does not touch the water. Heat, whisking constantly, until sugar is fully dissolved, or a thermometer registers 160°F. (Rub the mixture between two fingers to test for grittiness.)
  • Dry off bottom of the bowl and place back on the stand mixer. Whisk on high speed until the meringue is glossy and can hold stiff peaks, and the bowl is cooled, usually about 5 to 10 minutes, but could be longer.
  • Switch from the whisk to the paddle attachment.
  • Slowly add the cubed butter piece by piece, beating well on medium speed after each addition. When all the butter has been added, scrape down the sides of the bowl and raise the speed to medium-high. Beat until the buttercream is thick and fluffy. 
  • When buttercream is fluffy and smooth, add the salt, vanilla, melted chocolate, and espresso powder, and beat on medium-high until incorporated and buttercream is smooth.
  • Buttercream can be made ahead of time and frozen. To use, bring back to room temperature, then beat until smooth again.

Assembly:

  • Place the first layer of cake on a cake stand or plate. Top with frosting and spread evenly with an offset spatula or butter knife. (With all the butter in this buttercream, the hot water/spatula method isn't suitable here.) Repeat with remaining layers, then frost the whole cake in a thin layer; this is the crumb coat. Chill for 20 to 30 minutes.
  • Frost the top and sides of the cake, and smooth. Serve as is, or decorate as desired.

Notes

You can up this to 2 tablespoons if you want a really strong coffee flavor.