Grease and flour 9 x ... addition: sugar, eggs, chocolate and vanilla. Stir in flour, ... Cool slightly. While brownies are still warm to touch, ... and beat until thick.
Preheat oven to 350 degrees. ... inch pan. Melt chocolate chips and butter. Reserve. Combine ... in brown sugar, white sugar, and vanilla until thick. ... hours for easier cutting.
Beat butter at medium speed ... well. Add egg whites, sour cream, milk and ... your favorite creamy chocolate frosting over cooled brownies and cut into squares.