A Border Force worker from Stansted Airport quit his job by baking a resignation 'letter'.
Chris Holmes, from Sawston in Cambridgeshire, told airport bosses he wanted to devote "time and energy" to his family and business interests.
An image of the iced resignation went viral on Twitter within hours of Mr Holmes' brother-in-law posting it on the social networking site.
The Border Force said Mr Holmes "leaves with our best wishes".
Mr Holmes delivered the white iced resignation cake on Monday, his 31st birthday. He had worked at the airport as an immigration officer for four years.
He tweeted he was "overwhelmed by the positive response" from members of the public.
Bill Form, Border Force assistant director at Stansted, said: "Chris handed in the cake, along with a more formal letter, yesterday.
"He leaves with our very best wishes and we wish him well for the future."
Steven Livingstone tweeted: "His cake writing is better than my writing. Impressive."