PREHEAT oven to 350° F. Grease and flour 9-inch tube pan.
COMBINE flour, granulated sugar, cocoa, baking powder, baking soda and salt in large mixer bowl. Add 1 1/4 cups buttermilk, brown sugar, eggs, oil and 2 teaspoons vanilla extract. Beat with an electric mixer on medium speed for 2 minutes. Whisk in coffee until well blended. Pour batter into prepared pan.
BAKE for 35 to 40 minutes or until cake is set. Cool in pan on wire rack for 10 minutes. Remove from pan; cool completely on wire rack.
COMBINE powdered sugar, 3 to 4 teaspoons buttermilk, 1/2 teaspoon vanilla extract and coffee granules to make a smooth icing. Drizzle over cooled cake.