Fudgy Zucchini Brownies
["2 sq. (1 oz. each) unsweetened baking chocolate", "1/4 c. butter or margarine", "1 c. sugar", "1 egg", "1/4 tsp. baking powder", "1 tsp. vanilla", "2/3 c. flour", "1 c. shredded zucchini", "walnuts (optional)"]
["Preheat oven to 350\u00b0.", "Coat an 8-inch pan with vegetable cooking spray.", "Melt chocolate and butter in the top of a double boiler.", "Add sugar and mix well.", "Add egg, salt, baking powder and vanilla; mix until well combined."]
["chocolate", "butter", "sugar", "egg", "baking powder", "vanilla", "flour", "zucchini", "walnuts"]