Chocolate heaven with chocolate buttercream recipe

Ingredients

• 3 cups cake flour (not self-rising)
• 4 cups sugar
• 1½ teaspoons baking soda
• 1 teaspoon fine sea salt
• 9 ounces unsweetened chocolate (see Tip), finely chopped
• 2 cups hot freshly brewed coffee
• 1 tablespoon pure vanilla extract
• 4 large eggs, at room temperature
• 1 cup canola oil
• 1 cup sour cream, at room temperature

• 9 ounces semisweet chocolate, chopped
• ¾ pound (3 sticks) unsalted butter, at room temperature
• 2 tablespoons whole milk
• 1 teaspoon pure vanilla extract
• 2½ to 3 cups confectioners’ sugar, sifted

1. Position a rack in the lower third of the oven and preheat the oven to 350°F. Butter three 9-by-2-inch round cake pans, then line the bottoms with parchment and butter it as well. Lightly dust the pans with flour, tapping the pans on the counter to shake out the excess.
2. In the bowl of a stand mixer fitted with the paddle attachment (or in a large mixing bowl, using a handheld mixer), combine the flour, sugar, baking soda, and salt. Let the mixer run on low speed for 2 to 3 minutes to aerate the flour.
3. Meanwhile, put the chocolate in a medium bowl and pour in the hot coffee and vanilla. Let stand for about 2 minutes to melt the chocolate, then stir until smooth.
4. In another medium bowl, whisk the eggs and oil together until thick, satiny, and light in color. Whisk in the sour cream, being careful not to overmix; leave some visible streaks of white. Pour in the melted chocolate mixture and mix until just combined. Add the chocolate–sour cream mixture to the dry ingredients in thirds, mixing on medium speed until well blended.
5. Remove the bowl from the mixer and, using a rubber spatula, incorporate any ingredients hiding at the bottom of the bowl, making sure the batter is completely mixed.
6. Divide the batter evenly among the prepared pans and smooth the tops with a spatula. Tap the pans firmly on the countertop to remove any air bubbles from the batter.
7. Bake for 40 to 50 minutes, until the center of a cake springs back a little when touched and a cake tester inserted in the center of a cake comes out clean. The cakes will be a deep, dark chocolate brown with slight cracks on top. Let the cakes cool for 20 minutes, then remove from the pans and cool completely on a wire rack.
To Assemble the Cake
8. Level the tops of two of the cake layers with a serrated knife so they’re flat. Place one layer cut side down on a flat serving plate (you can keep the edges of the plate clean by sliding strips of parchment under the cake while you frost it). Using an offset spatula, spread the top with a big dollop of frosting. Place the second cake layer cut side down and spread the top with another big dollop of frosting. Place the final layer on top, right side up, and frost the top and sides with the remaining frosting, making big luscious swirls with the spatula. The cake can be stored in an airtight container at room temperature for up to 2 days.
Chocolate Buttercream
9. Put the chocolate in a heatproof bowl set over a simmering saucepan of water (do not let the bottom of the bowl touch the water) and stir occasionally until the chocolate is completely melted. Set the chocolate aside to cool to room temperature.
10. In the bowl of a stand mixer fitted with the paddle attachment (or in a medium mixing bowl, using a handheld mixer), beat the butter on medium speed until smooth and creamy. Add the milk, mixing until completely blended. Add the cooled chocolate and mix until completely incorporated, 2 to 3 minutes, scraping down the sides of the bowl with a rubber spatula as necessary. Add the vanilla and beat just until mixed. With the mixer on low speed, gradually add 2½ cups confectioners’ sugar and continue beating, adding more sugar as needed, until you reach a creamy, silky frosting consistency. The frosting can be stored in an airtight container at room temperature for up to 2 days.
11. Add the milk, mixing until completely blended. Add the cooled chocolate and mix until completely incorporated, 2 to 3 minutes, scraping down the sides of the bowl with a rubber spatula as necessary. Add the vanilla and beat just until mixed. With the mixer on low speed, gradually add 2½ cups confectioners’ sugar and continue beating, adding more sugar as needed, until you reach a creamy, silky frosting consistency. The frosting can be stored in an airtight container at room temperature for up to 2 days.