Brownies: Combine flour, baking powder and salt in a small bowl. Heat water and espresso in a saucepan over low heat, stirring to dissolve. Add sugar and butter. Cook, stirring constantly, until mixture comes to boil. Remove from heat, stir in 1 cup chocolate chips until smooth. Add eggs, one at a time, stirring well after each addition. Stir in flour mixture and pour into a greased 9 inch square baking pan. Bake at 350F for 25 to 30 minutes or until a wooden pick inserted in the center comes out slightly sticky. Cool completely.
Frosting: Heat cream and espresso in small saucepan over low heat, stirring to dissolve espresso. Add chocolate chips, stirring until smooth. Remove from heat, stir in powdered sugar. Chill until frosting is of spreading consistency. Spread onto brownies.