01 -
Preheat the oven to 350°F. Butter two 8-inch round cake pans and line the bottoms with parchment paper discs.
02 -
In a large bowl, whisk together all the dry ingredients well.
03 -
In a separate bowl, whisk together all the wet ingredients, except for the coffee.
04 -
Slowly add the wet ingredients to the dry ingredients, mixing as you go. Once incorporated, add the hot coffee and mix until no pockets of dry flour remain. The batter will be very thin.
05 -
Divide the batter evenly between the two prepared cake pans. Bake for 35 minutes or until risen and a toothpick inserted into the center comes out clean.
06 -
Allow the cakes to partially cool in the pans. Then turn them out onto a cooling rack and let them cool completely before frosting.
07 -
Melt the semisweet chocolate in a double boiler or microwave using short bursts. Stir until smooth and set aside to cool slightly.
08 -
In the bowl of a stand mixer with the paddle attachment, beat the room temperature butter for 2 minutes until smooth and lighter in color.
09 -
Slowly beat in the powdered sugar, salt, and vanilla until smooth. Whisk the sour cream into the partially cooled chocolate, then add to the butter mixture. Beat on low speed until smooth and combined. Refrigerate if needed to adjust consistency before frosting.
10 -
Spread the frosting over the cooled cake layers, smoothing it evenly. Optionally, apply a crumb coat first for a cleaner finish.