Cake:Preheat oven to 325 degrees. Grease and flour a 13x9x2inch baking dish. Set aside. Cream sugar and shortening until light ad fluffy. Add eggs and beat at low speed until well blended. Combine salt, cocoa and flour in a separate bowl. Blend well. Add to creamy mixture a little at a time until well blended. Stir in vanilla and nuts. Pour into a 13X9X2 inch baking pan that has been greased and floured. Bake 35 to 40 minutes at 325 degrees. Remove from oven and cover entire top with the marshmallows
Frosting: In a large saucepan, add butter. cocoa powder',milk and confectioner's sugar. Blend well. Cook on medium heat at a good boil for about three minutes. Remove from heat and add in vanilla and nuts. Stir. Pour hot frosting on top of the hot cake. Cool..Put into the fridge and let chill for a couple of hours before cutting.