CAKE: Combine sugar, flour, cocoa, baking soda and salt in large mixing bowl. Mix well. Heat butter and water in saucepan until boiling. Pour over dry ingredients and mix. Beat in buttermilk, eggs, and vanilla. Pour thin batter in greased and floured 15x10-inch pan. Bake in 200ºC oven 20 minutes. Serve warm or cold. FROSTING: Combine butter, cocoa, and milk. Heat to boiling. Pour over sugar and nuts. Mix well. Spread on hot cake. NOTE: I like to substitute strong coffee for the milk and add half ts vanilla to the frosting. This cake is reminiscent of "Texas Brownies." ----