Melt butter and chocolate in microwave or double boiler. Cool. If you don't
cool, brownies will be heavy and dry.
Beat eggs and salt together until light and foamy. Gradually beat sugar into
the egg mixture. With a few quick strokes with a wooden spoon, combine the cooled
chocolate mixture into the eggs and sugar. Before the mixture becomes uniformly
colored and well blended, fold in flour. Before flour is fully blended in, fold
in nuts. Pour batter into a greased 13 x 9-inch pan.
Bake for 25 minutes. Cool.
Chocolate Frosting: Melt shortening and chocolate in saucepan over low heat. Stir in remaining ingredients
and beat until smooth. Place pan of frosting in bowl of ice water and continue beating
until it is of spreading consistency. If desired, stir in 1/2 cup finely chopped
nuts. Frost brownies and serve with vanilla ice cream, if desired.