In large saucepan over low heat, melt margarine and chocolate, stirring constantly until smooth. Remove from heat and spoon flour into measuring cup; level off. Stir in flour, sugar, nuts, baking powder, salt and eggs; mix well. Cover with plastic wrap and refrigerate at least 1 hour (but up to 24 hours).
Preheat oven to 300F. Shape dough into 1-inch balls; roll each in powdered sugar. Place 2 inches apart on ungreased cookie sheets. Bake for 13-18 minutes or until set. Immediately remove from cookie sheets and cool completely.
Nutrition Info Per Serving: Calories 88 Total Fat 3 g Cholesterol 18 mg Sodium 58 mg Potassium 38 mg Total Carbohydrate 14 g Dietary Fiber 1 g Sugars 10 g Protein 2 g