Preheat oven to 350F. Lightly oil an 8" square baking pan. Place chocolate in heat-proof bowl. Set over low heat in small skillet containing 1/2" simmering water. Stir occasionally, just until chocolate is melted. Remove from heat; set aside. In mixer bowl combine all ingredients except flour and walnuts. Beat to blend thoroughly. Mix in flour. Spread batter in prepared pan; sprinkle with walnuts. Bake until center top of brownies springs back to the touch, about 30 minutes. Cool on rack. Cut into 2" squares. Makes 16 brownies. NOTES : For prune puree: In food processor or blender, chop 1-1/3 cups pitted prunes. With machine running, add 1/2 cup water. Puree, stopping to scrape sides, until mixture resembles smooth paste, about 5 minutes. Recipe by: January 1997 Vegetarian Times