Preparation :

Mix flour and sugar in a large bowl. In a medium saucepan, combine butter, water, and cocoa over medium heat. Bring mixture to a boil and pour over the flour/sugar mixture. Mix well. Add eggs, buttermilk, baking soda, and vanilla. Pour into a well-greased 9×13 pan, and bake at 350 for 30 minutes.

Mix flour and sugar in a large bowl. In a medium saucepan, combine butter, water, and cocoa over medium heat. Bring mixture to a boil and pour over the flour/sugar mixture. Mix well. Add eggs, buttermilk, baking soda, and vanilla. Pour into a well-greased 9×13 pan, and bake at 350 for 30 minutes.