I also started researching the origins of the story. Although they are probably lost to history, the story itself is a wonderful example of an urban legends. And there are some truly wonderful and mind-boggling urban legends out there. There are myriad Web sites devoted to the cookie story. Neiman Marcus itself, has a page devoted to the cookie story which you can find by clicking the Customer Service link on the department store's home page and then clicking cookiemonster.
Any good story demands a parody.
He was the English boy with brain cancer whose dying wish was to receive so many get well cards that he'd be included in the Guinness Book of World Records. He recovered after surgery. He set the record. Guiness retired the category. So check them out.