In a mixing bowl combine sugar, eggs, salt, baking soda, vanilla and margarine together and mix. Then add the flour, cocoa, buttermilk, and nuts if choosing to. Mix with hand mixer until smooth.
Pour batter into a greased, large jelly roll pan (17"x 12" x 2" or so).
Bake at 350 degrees F. for 25 to 30 minutes.
As soon as the cake is done, make the icing. In a sauce pan combine margarine, cocoa, and buttermilk together as margarine melts. Then add the powdered sugar and vanilla. Stir until smooth. Add nuts if choosing to. Pour immediately over the warm cake and spread over top and edges of the cake.
Make it with nuts, any kind of nuts you'd like, or without depending on your liking.
Recipe by Stacy Walker - www.thebackroadlife.com