In a food processor or blender, coarsely grind the cranberries. Mix in 1 cup of the sugar. Cover and place in the icebox for 6 hours or overnight.
In a large bowl, whip the cream with the remaining ¼ cup of sugar until stiff.
Fold in the cranberries, marshmallows, pineapple and pecans, if using.
Cover and place in the icebox for 1 hour or until chilled. Serve cold.