Step 1

In a sauce pan, bring Coca-Cola, oil, margarine, and cocoa to a boil.

Step 2

In a separate bowl, mix the sugar, flour and salt and pour in the boiling liquid and beat well.

Step 3

Add the eggs, buttermilk, soda and vanilla and beat well.

Step 4

Pour into a greased and floured sheet cake pan, and bake at 350°F for 20 - 25 minutes.

Step 5

In a saucepan, combine the butter cocoa, and milk and heat until the butter melts.

Step 6

Beat in the remaining ingredients.

Step 7

Spread on the hot cake.

Step 8

Cool and cut.

Step 9

Serve topped with natural vanilla bean ice cream.