Preheat the oven to 400 degrees F
Whisk together flour and sugar in a large bowl
Put the unsweetened chocolate in a pot and melt over medium low heat
Add chocolate syrup, butter, oil and water to the melted chocolate
Whisk together and let it come to a soft boil
Pour the chocolate mixture over sugar and flour and whisk well
Add buttermilk, eggs, baking soda and vanilla to the mixture
Whisk well to combine
Lightly butter and flour a 9x14 pan
Pour the cake batter into the pan
Bake for about 20 minutes
Start the icing as soon as the cake comes out of the oven
Combine butter, milk and cocoa powder in a pot and bring to a boil
Remove from heat and add powdered sugar
Whisk well to combine
Pour icing onto hot cake and spread
