"GERMAN CHOCOLATE CAKE" isn't German
German chocolate cake is an American invention which is called that because it originally used a particular brand of baking chocolate: Baker's German's Chocolate. That type of chocolate was invented by an employee of the baker Chocolate Factory (which is right around the corner from my house) named Sam German. He was from Texas, I think.
It's called german chocolate cake because of old Sam german, not because it had anything to do with the country of Germany.
To make a traditional german chocolate cake you need to use a particular type of chocolate -- Baker's German's or an equivalent. That's what made it distictive. Otherwise it will be your basic chocolate cake.
Baker's German's comes in a green box with a picture of German Chocolate cake on it.