In a microwave-safe bowl, melt butter and chocolate; stir until smooth. Stir in sugar and vanilla. Add eggs, one at a time, stirring well after each addition. Combine flour and salt; stir into chocolate mixture until combined. Stir in pecans.
Spread into a greased 13-in. x 9-in. baking dish. Bake at 325° for 35-40 minutes or until a toothpick inserted near the center comes out clean. Cool on a wire rack.
For frosting, in a small heavy saucepan, melt butter and chocolate over low heat; stir until smooth. Remove from the heat. Stir in the confectioners' sugar, milk and vanilla until blended.
Frost brownies; score into 24 bars. Using a small star-shaped cookie cutter, lightly press a star outline in the center of each brownie. Outline stars with red, white and blue icing. Yield: 2 dozen.