Note: you will want to start this recipe the night before, or very early in the morning. Total prep time is less than 10 minutes, but it needs several hours to soften the marshmallows.
Drain your crushed pineapple, and stir it in with the cranberry sauce and marshmallows. Cover and refrigerate. The marshmallows will be a little bit chewy, so you want them to soak and soften. You can also take this time to make sure you put your Cool Whip in the frig to thaw. :)
When you are closer to dinnertime, fold in the cool whip until it's well-blended. You can do this ahead of dinner - it doesn't need to be served immediately, but you will want to put it back in the frig until you're ready to serve it.
Recipe by Happy Hour Projects at https://happyhourprojects.com/cranberry-marshmallow-salad-and-a-virtual-potluck/