Combine first 3 ingredients, stirring well. Set aside.
Combine sugar, shortening, and water in a medium saucepan. Bring to a boil over medium heat, stirring constantly; remove from heat. Add chocolate morsels and vanilla, stirring until smooth.
Add eggs, one at a time, stirring after each addition. Add flour mixture and walnuts; stir well.
Spoon into a greased 9" square pan. Bake at 325° for 30 minutes or until a wooden pick inserted in center comes out clean.
Sprinkle bourbon evenly over warm brownies. Cool completely in pan on a wire rack. Spread White Frosting over uncut brownies. Pour warm Chocolate Glaze over frosting. Let stand until set. Cut into squares.