In a large saucepan over low heat, melt margarine and chocolate, stirring until smooth. Remove from heat; cool slightly. Lightly spoon flour into a measuring cup; level off. Stir in flour, sugar, walnuts, baking powder, salt, and eggs; blend in well. Cover; refrigerate at least 1 hour for easier handling. Heat oven to 300?. Shape mixture into 1 inch balls; roll in powdered sugar (coat heavily). Place 2 inches apart on ungreased cookie sheets. Bake at 300? for 15 - 18 minutes or until edges are set. Remove from the cookie sheets immediately. 4 dozen cookies. OINK !