Add the cranberries to a food processor and pulse until they are well chopped, but not mushy.
Pour the cranberries into a large bowl. Stir in the sugar and pineapple and mix well. Cover and refrigerate for an hour or longer. Drain most of the juice.
In a medium bowl, beat the cream cheese until smooth. Pour in the cream and whip until stiff peaks form. Fold the creamy mixture into the salad. Fold in marshmallows.
Cover and refrigerate for several hours or overnight.
To Store: Store cranberry salad covered, in the refrigerator for 2-3 days.Make ahead Instructions: I definitely recommend making cranberry salad ahead of time. In fact, for best results, make it 1 day before serving.