In a saucepan over low heat, melt the chips and butter; pour into a mixing bowl. Beat in sugar till smooth. Add eggs, one at a time, beating well after each. Combine hot water and coffee granules; add to the chocolate mixture. Combine the flour, cocoa and baking powder; beat into chocolate mixture.
Spread into a greased 13x9 pan. Bake at 350 for 15 - 20 min or till toothpick inserted near center comes out clean. Cool in pan.
For mousse, in a small mixing bowl, beat cream cheese until smooth; beat in milk and melted chips. In a saucepan, sprinkle gelatin over cold water; let stand for 1 min. Cook and stir over low heat until gelatin is dissolved. Remove from heat; stir in coffee granules until dissolved.
In a mixing bowl, beat whipping cream until slightly thickened. Beat in gelatin. Fold into cream cheese mixture. Spread over brownies. Cover and refrigerate for 3 hours or until firm. Cut into squares. Store in fridge.