Preheat oven to 350F. Line 12 2-3/4" muffin cups with paper liners. In food processor, puree prunes and 1/2 cup water until smooth. Scrape puree into large bowl. With electric mixer, beat together prune puree and 1/2 cup water. Add egg whites and vanilla; beat until thoroughly combined. Stir in remaining ingredients; mix completely. Spoon batter evenly into prepared cups, filling each about 2/3 full. Bake 10 to 12 minutes, until toothpick comes out clean. Remove from pan; cool on rack. Sprinkle evenly with powdered sugar. Weight Watcher Exchanges: 1/2 Bread, 80 Optional Calories. Nutritional Analysis per serving: 122 calories, 3 g. protein, 28 g. carbohydrate, 1 g. fat, 130 mg. sodium, 0 mg. cholesterol. Calories from fat: 7% Original recipe from Weight Watchers magazine, March 1993. Conversion and additional nutritional analysis by Rick Weissgerber [GEnie D.WEISSGERBE]