In a mixing bowl, beat sugar, eggs and vanilla. Add butter; mix well. Combine dry ingredients; add to batter and mix well. Pour into a greased 20 cm square baking pan. Bake at 180ºC or 25-30 minutes or until brownies test done with a wooden pick. Cool in pan on a wire rack. For frosting, combine butter, cocoa, water and coffee, mix well. Gradually stir in sugar until smooth, adding additional warm water if necessary to achieve a spreading consistency. Frost the brownies.