Preparation

• Heat oven to 350°F. Melt 1/2 cup butter and 2 squares chocolate in 2-quart saucepan over medium heat, stirring constantly, until smooth (4 to 6 minutes). Stir in all remaining brownie ingredients until well mixed. Spread into greased 8-inch square baking pan.
  Bake for 25 to 30 minutes or until brownie just begins to pull away from sides of pan. Cool completely.
  Combine all filling ingredients except chocolate in small bowl. Beat at medium speed until creamy. Spread over cooled bars.
  Drizzle with melted chocolate. Cool completely; cut into bars. Cover; store refrigerated.