Cook 1/2 cup sugar and 2 tablespoons water in heavy small saucepan over low heat, stirring until sugar dissolves. Transfer to top of double boiler. Add cranberries. Cover berry mixture and place over simmering water. Cook 45 minutes, stirring occasionally. Remove from over water. Let cranberry mixture stand at room temperature overnight.
Place remaining 1/2 cup sugar on plate. Drain cranberries well. Add to sugar and turn to coat. Let dry at least 30 minutes. (Can be prepared 3 days ahead. Cover and refrigerate.)