Radio 1 boss Andy Parfitt spent £125 on a cake to celebrate DJ Chris Moyles becoming the longest-serving host of the breakfast show and then claimed the cost back on expenses.
Parfitt bought the gift on September 5 last year but only claimed the money back in the latest round of expense claims.
A BBC spokeswoman said: "The cake was bought for the breakfast show team to mark them becoming the longest-running breakfast show in Radio 1's history. This was a way of saying thank you to the seven people involved in making the show."
BBC staff normally have to submit expenses within three months and any claims after that must be approved by a manager.
Parfitt, who has been in charge of the station for 12 years, defended the controversial DJ last month after a half-hour on-air rant about pay.
He admitted it was not "the best Chris Moyles programme I've ever heard" but said he did not think the presenter had "not crossed the line".
Moyles, one of the BBC's highest earners, drew criticism for devoting a section of his show to talking at length about how he had not been paid.
During his rant, Moyles hit out at BBC bosses, accusing them of "a huge lack of respect" for failing to pay his wages.
He said he was "very, very angry" about the situation and asked "why should I come in?".
As listeners texted in about his diatribe, he began criticising them, telling one: "If you really have a problem with that, I'm telling you now I'll pay your licence fee and you can switch off and listen to someone else. Go and read the Daily Mail, you miserable fart."