1) Cake:Preheat oven to 350 F (180C).In a large saucepan, bring to a boil the water, cocoa, oil and butter or margarine.

2) Mix the flour, sugar, salt and soda in a large mixing bowl.

3) Whisk in the hot mixture and mix well.To this add the buttermilk, vanilla and the beaten eggs; continue mixing.

4) Pour the batter into a greased and floured 9"x13" oblong baking pan.

5) Bake in the preheated oven for approximately 20 minutes or until a toothpick comes out clean when inserted in the middle.

6) Remove from the oven and frost while still warm.Frosting:In a large pan set over medium heat, melt the butter and the cocoa powder and milk.Stir in the sugar and vanilla; whisk until smooth.

7) Add the chopped nuts if desired; stir well and spread on the warm cake.

8) Let cake cool before serving.