Cake: Bring butter and water to a boil in a medium sized saucepan. While mixture is boiling, whisk together the flour, sugar, and salt in a large mixing bowl.

Pour hot mixture over dry ingredients and beat well.

Whisk together baking soda, sour cream, eggs, and flavorings in a small bowl. Add to mixing bowl and beat till smooth.

Pour into a well greased 10"x15" sheet pan with sides. Bake at 375° for about 20 minutes or until a toothpick comes out clean.

For frosting: Bring butter, cocoa, salt, and milk to a boil in a small saucepan. It may appear curdled- that's fine.

While mixture is boiling, measure 3 1/2 cups of the powdered sugar into a mixing bowl. Pour boiling chocolate mixture over powdered sugar. Beat till smooth and add vanilla. Add more powdered sugar if needed.

Pour over cake after it has cooled for about 5 minutes.