If you're not a big fan of a frozen cocktail, you can easily make a really good pina colada on the rocks. In the blender, add fresh pineapple chunks or frozen cubes of pineapple chunks that you have thawed. Add the other ingredients and give everything a good blitz until well blended. Pour the mixture in cocktail shaker filled with ice and shake, shake, shake! Using a cocktail strainer, pour the mixture in a highball glass over ice cubes or crushed ice and enjoy! It tastes just as good as the frozen version!