place rinsed cranberries in a large microwave safe bowl, add sugar and water and stir. microwave on HIGH for 5 minutes, stir, then microwave on HIGH for another 5 minutes. Remove from oven and let cool on the counter for 30-60 minutes.
When cooled to room tempurature, add the drained crushed pineapple, vanilla, and orange juice. Place in refrigerator to chill for at least 2 hours.
Just before serving, remove from fridge, stir in the walnuts (if using) and sprinkle orange zest on top. Enjoy!