Preheat oven to 350^. Butter bottom only of 9-inch square baking pan. Dissolve freeze coffee in the boiling water in a large bowl. Add brownie mix, sour cream, melted butter and eggs; mix well. Spread batter into prepared pan. Bake 25-30 minutes or until brownies begin to pull away from the sides of pan and center is just set(do not over bake). Place on wire rack to cool completely.
Stir cheese until soft, add whipping cream, sugar and vanilla. Continue stirring until mixture is smooth. (Overmixing will cause curdling). Spread topping over brownies.
Cut into 9 pieces. Garnish with cocoa,chocolate shavings or nuts. Cover lightly and chill until serving time. Refrigerate and leftovers.