Combine first 3 ingredients in a medium bowl; stir well. Set flour mixture 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 dry ingredients and walnuts; stir well. Spoon into a greased 9-inch 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. Let cool completely in pan on a wire rack. Spread White Frosting on top of brownies. Pour warm Chocolate Glaze over frosting. Let stand until set. Cut into squares.