Confectioners' sugar, optl In a bowl, combine brown sugar, butter and maple flavoring. Beat in the eggs, one at a time. Combine flour and baking powder; add to egg mixture. Stir in walnuts. Pour into a greased 9-inch square baking pan. Bake at 350 degrees for 30 minutes or until brownies test done. Cool. Dust with confectioners' sugar if desired.