Place brownies on tray.
Prepare mousse: Mix whipped topping, raspberry extract and half the raspberry fruit filling.
Prepare satin chocolate sauce: In top half of double boiler, combine both chocolates over simmering water. Stir constantly until melted, then whisk in the corn syrup and water without removing the double boiler from the heat; whisk until smooth and shiny. Let cool to room temperature before using.
Top brownies with mousse, drizzle with satin chocolate sauce. Chill until ready to serve.
To serve, cut into 12 - 15 squares. Divide remaining raspberry filling among plates before plating brownies. Top each brownie with a swirl of cool whip and fresh berries and mint.