A man who worked for four years for the Border Agency at Stansted Airport has handed in his notice written in icing on a cake.
Chris Holmes, 31, from Cambridgeshire told bosses he wanted to focus on his cake business full-time after recently becoming a father.
"I now realise how precious life is and how important it is to spend my time doing something that makes me, and other people, happy," the cake read.
Mr Holmes told ITV News: "It just seemed like the obvious choice, having set up a cake company, I thought I would leave them with a memento that would be a nice way of remembering me."
The image went viral after it was circulated on the internet, but Mr Holmes said his boss reacted well.
He said: "I think he was pleasantly surprised. Of all the resignations businesses get, I think that's probably a nice way for an employee to leave and I hope they enjoyed the cake as well as the resignation."
The cake Mr Holmes handed in at work was a passion cake, made of spiced carrot with pecans, sultanas, coconut and orange butter cream inside.
Mr Holmes, who had worked as an immigration official for almost four years, said he started by making cakes in the evening and at weekends.
As the business became more successful, he dropped down to part-time work at the airport.
He told BBC Cambridgeshire: "I was hoping at some point I'd be able to resign from my other job and make this full-time."
"I think the requirements were that I hand in written notice so I thought, it doesn't say what it has to be written on, so there you go." He said.
Mr Holmes said he was amazed by the reaction, and had no idea the photo, which he originally posted on a private Facebook account, would get such a big response.
"I thought it would get a few likes from my friends on Facebook and here we are," he told BBC Cambridgeshire.
"It's been so manic I haven't had time to actually kind of gauge the reaction and see what's happened."
The note finishes by reminding his colleagues that if they enjoy his resignation letter, they can order more cakes through his firm, Mr Cake.
Orders have already been received from Sweden, Italy and Canada, according to the firm's Twitter account.