For icing, beat butter and shortening in large bowl with electric mixer until light and fluffy. Gradually add sugar, one cup at a time, beating well on medium speed. Scrape sides and bottom of bowl often. When all sugar has been mixed in, icing will appear dry. Slowly add 2-3 tablespoons bourbon; beat at medium speed until light and fluffy. Add half the melted candy; beat until well combined, scraping bottom and sides of bowl often. For ganache, heat cream until steaming; whisk into second bowl of melted candy until well combined