Mix flour, salt, soda, and cranberries in large bowl.
Mix molasses and boiling water in small bowl. Add to flour mixture; mix well. Pour into prepared mold. Cover mold and put in large kettle. Pour 3 inches of water into kettle. Bring water to a boil; reduce heat and cover kettle. Steam pudding for 3 hours. Remove pudding from mold. Serve warm with sauce
For sauce, melt butter in medium pan over low heat. add sugar and cream. Cook til slightly thickened. Stir in vanilla. Serve warm on pudding.
Note: Pudding may be made in advance, refrigerated or frozen and rewarmed in kettle before serving. Serves 10