For the brownies:

• In a saucepan, melt butter. Remove from the heat. Stir in cocoa and cool. In a large bowl beat eggs and sugar until blended. Combine flour, baking powder and salt; gradually add in egg mixture. Stir in vanilla and the cooled chocolate mixture until well blended.
• Spread into a greased 13 x 9 - inch baking pan. Bake at 350 degrees F. for 25 - 28 minutes or until a toothpick inserted near the center comes our clean. Do not overbake. Cool on a wire rack.
• For the frosting: In a large bowl, cream butter and confectioners' sugar until light and fluffy. Beat in the cocoa and vanilla. Add enough milk until the frosting becomes a spreading consistency. Spread on brownies in pan. Cut into squares.