Grease an 8 x 8 x 2 inch baking pan; set aside.
In a medium saucepan combine sugar, butter, and water. Cook and stir over medium heat just until mixture boils. Remove from heat. Add chocolate pieces, stirring until melted. Add eggs and vanilla, beating with a wooden spoon just until combined.
Combine baking soda, flour, and salt. Stir flour mixture and pecans into chocolate mixture. Spread in the prepared pan.
Bake in a 350°F oven about 20 minutes or until edges are set and begin to pull away from pan.
Using a fork, prick warm brownies several times. Drizzle bourbon evenly over brownies. Cool in pan on a wire rack.
Spread Butter Frosting over brownies; drizzle with melted chocolate. Cut into bars.
BUTTER FROSTING: In a small bowl beat 3 tablespoons butter with an electric mixer on medium to high speed for 30 seconds. Gradually add 1 1/2 cups sifted powdered sugar, beating well. Slowly beat in 2 teaspoons milk and 1/4 teaspoon vanilla. If necessary, beat in enough additional milk to make a frosting of spreading consistency.
* If you prefer not to cook with alcohol, simply omit the drizzling step. *