Taken from this page at Snopes.com

1. For my 40th birthday, my husband decided to surprise me with a birthday cake from our local bakery. “In the middle please print ‘Happy Birthday Nita,'” he instructed them over the phone. “Then, ‘you’re not getting older’ at the top and ‘you’re getting better’ at the bottom.” When he went to pick it up, he discovered that they had decorated the cake with the words exactly as he had said them. “Happy Birthday Nita, you’re not getting older at the top, you’re getting better at the bottom.” [www.readersdigest.ca, 1997]

2. When my mother-in-law ordered a cake for my wedding anniversary, she made a point of instructing the bakery, “That’s Thompson with a ‘p’.” Later when she went to pick her order up, she noticed that on the box they had written “Mrs. Phompson.”
[Collected via e-mail, October 2007]

3. We had a “going away” party yesterday for a lady at our Little Rock claim office. One of the supervisors called a Wal-Mart and ordered the cake. He told them to write: “Best Wishes Suzanne” and underneath that write “We will miss you.”

As the picture shows, it didn’t quite turn out right. It was too funny not to keep it.

4. There’s a married couple whose birthdays fall on the same date, which they naturally celebrate pretty lavishly. Just before their last birthday, the lady stopped in at her neighborhood bakeshop and ordered a cake with “Happy Birthdays” on it. “You see, two of us are having a birthday,” she explained to the clerk. “So I want it to say ‘Happy Birthdays’ — plural.”

The clerk wrote the instructions down carefully, and sure enough, when the cake was delivered, it had “Happy Birthdays Plural” on it. [Sydney Morning Herald, 2003]

5. When Marlyn Wade ordered a birthday cake for her husband in a tres chic French patisserie in Murwillumbah, the assistant (with a delightful French accent) asked if it was for “a guy or a girl”. “A guy,” Marlyn assured him. “But,” says June Howard, Marlyn’s mother, “on picking it up later, she read on the work of art in blue icing – Happy birthday Guy. Her husband’s name is Peter. Delicious cake, though!” [Sydney Morning Herald, 2003]

6. It’s always risky ordering cakes to be iced. Liz Ralston, of Frenchs Forest, who belongs to Inner Wheel, a worldwide organisation of partners of Rotarians, phoned a patisserie and ordered a special cake for the Ryde Inner Wheel Club. The cake came, inscribed: Ride in a Wheel. Read More »