Double Down

I've seen advertisements for the new Really Big Chicken Sandwich at Jack in the Box. It is essentially a double chicken sandwich which got me thinking about the double cheeseburger. I love a good burger as much as the next guy but I wonder whose idea it was in the first place. Like some guy was cooking burgers and another guy came along and said, "You know what would go great on top of that burger?"

"What, man? Lettuce? Mayo?"

"No man, another burger." Minds were blown at that exact moment in 1942.*

* - Random guess at a year when the double cheeseburger may or may not have been invented