Not a cocktail but a few people have asked for a shrub recipe so I figured it start with a fun one. Keep in mind this is my way. I encourage you to read up a little and decide what works best for you.
4 cups pineapple
5.5 cups distilled white vinegar
4 cups sugar
Place fruit and vinegar in a jar and seal tight. Let sit for up to a month. It will equalize after that and not yield much extra sugar(s). Strain off fruit and cook or eat it as desired. Add sugar and mix well. This is fairly stable and more or less a vinegar but I still refrigerate mine.