Line 8-inch square pan with foil, extending foil over edges. Lightly butter foil.
In large saucepan, melt chocolate chips over very low heat, stirring until smooth. Remove from heat; stir in frosting.
In small bowl, dissolve espresso powder in water. Stir into fudge mixture, mixing until well blended. Spread in buttered foil-lined pan. Refrigerate about 1 hour or until firm.
Remove fudge from pan by lifting foil; remove foil from fudge. Cut into squares; garnish each with coffee bean.