1. Process frozen pineapple chunks and next 4 ingredients in a blender until smooth, stopping to scrape down sides. Garnish, if desired; serve immediately.
Note: We tested with bagged frozen pineapple from the freezer section, fresh pineapple we froze in the Test Kitchens, and canned pineapple chunks (in juice) that we placed in the freezer (can and all). After opening the frozen can, we let hot water run over the top for about 10 seconds and then used a fork to pull out 2 cups worth of pineapple. (Tip: Canned pineapple can be frozen up to 3 months.)