• Preheat oven to 350°F. Grease and flour two 8-inch round cake pans and line the bottoms with parchment paper.
• In a large bowl, sift together flour, cocoa powder, granulated sugar, baking powder, baking soda, and kosher salt. Whisk to combine evenly.
• In a separate medium bowl, whisk together hot brewed coffee, buttermilk, vegetable oil, eggs, and vanilla until smooth and well blended.
• Pour the wet ingredients into the dry ingredients. Mix gently until the batter is completely smooth. The batter will be thin, and that’s okay.
• Divide the batter evenly between the prepared pans. Bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out with moist crumbs, but no wet batter.
• Let the cakes cool in the pans for 10 minutes, then turn them out onto wire racks. Remove parchment and let cool completely before frosting.

Chocolate Buttercream Frosting

• To make the frosting, in a large bowl using a hand mixer or stand mixer fitted with the paddle attachment, beat the softened butter until creamy and light, about 2 minutes.
• Add the cocoa powder and mix until fully incorporated and smooth.
• Gradually add the confectioners’ sugar and heavy cream, alternating between them. (Add a portion of sugar, then a small amount of cream, and beat until light and fluffy.) Repeat this process until all the sugar and cream are incorporated.
• Mix in the vanilla extract and a pinch of kosher salt. If the frosting is too thick, add a little more cream, one tablespoon at a time, until spreadable. (I added an extra 2 tablespoons of heavy cream.)

Frosting the Cake (Two Layers)

• Place one cooled cake layer on a serving plate or cakeboard.
• Spread ¼ to ½ cup of frosting evenly over the top.
• Gently place the second cake layer on top.
• Use the rest of the frosting to cover the top and sides of the cake. Smooth with a spatula or knife.
• Optional: Decorate with sprinkles, chocolate shavings, or any fun toppings!