* Chocolate should be melted and cooled. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Cream butter and sugar; beat in eggs. Blend in chocolate and vanilla. Stir flour with baking powder and salt. Add to creamed mixture; mix well. Stir in nuts. Spread in greased 9 X 9 X 2-inch baking pan. Bake at 350 degrees F for 25 to 30 minutes. Cool. If desired, sift opwdered sugar over top. Cut into bars. Makes 24 brownies.