
2 cups all-purpose flour
2 cups granulated sugar
1 cup Dutch-process cocoa powder
2 teaspoons baking soda
1 teaspoon baking powder
1 teaspoon coarse kosher salt
1 cup buttermilk, room temperature
½ cup vegetable oil
2 large eggs, room temperature
1 tablespoon pure vanilla extract
¾ cup hot brewed coffee
¼ cup Dutch-process cocoa powder
¼ cup boiling water
1½ cups salted butter, softened
1 cup powdered sugar, sifted
⅛ teaspoon coarse kosher salt
2 cups semisweet chocolate chips, melted and cooled
Desired garnishes: chocolate curls, blueberries, cocoa powder and/or fresh rosemary sprigs