Meanwhile, beat shortening and butter in large bowl with mixer until blended. Add vanilla. Stir in icing sugar, one cup at a time, beating well on medium speed. Add milk; beat until light and fluffy. Divide icing into 2 bowls; add yellow food colouring to one bowl and red food colouring to other bowl; mix well. Spread entire cake with thin layer of yellow icing. Add yellow and red icing to two separate piping bags with large star tip. Starting with red icing bag, decorate cake with eight large flowers. With yellow icing bag, decorate remainder of cake. Add licorice pieces to top of cake to form handles and purse clasp.