• 1 cup (2 sticks) unsalted butter, softened at room temperature
• 3 cups light brown sugar, packed
• 4 eggs
• 2 teaspoons pure vanilla extract
• 3/4 cup unsweetened cocoa powder
• 1 tablespoon baking soda
• 1/2 teaspoon salt
• 3 cups sifted cake flour
• 1 1/3 cups sour cream
•  1 1/2 cups hot coffee
• Frosting:
• 8 tablespoons (1 stick) unsalted butter, softened at room temperature
• 16 ounces cream cheese, softened at room temperature
• 8 ounces unsweetened chocolate, melted
• 1/2 cup cooled coffee
• 4 teaspoons pure vanilla extract
• 6 cups confectioners' sugar

PREPARATION: