A Florida mom was overwhelmed when a cake she had preordered from Publix for her son’s birthday last month had been anonymously paid for. Melanie Andrews Pitts had ordered the cake from the supermarket at Fleming Island shopping center in advance of her son Graham’s 18th birthday. On the afternoon of May 14, Melanie went to the bakery department to pick up the cake; little did she know that she was in for more than just a sweet treat. The lady at the bakery counter informed her that the cake had already been paid for; upon inquiry, Melanie was told that a note, which had been left inside the package, would explain it all. “Hello, today is my son’s 36th birthday, his 4th one in Heaven,” the note read. “I wanted to honor and remember him by paying it forward. I paid for your loved one’s birthday cake. “It is my hope that you …