Ivan González was slapped with the fine after a policeman spotted him eating the breakfast pastry while riding through central Sabadell, in Spain's Catalonia region.
He was on his way to work when a local policeman waved him down and wrote up a ticket for reckless driving, Spain's La Vanguardia newspaper reported on Thursday.
An indignant González said he planned to appeal the decision.
Even police at the local station appeared confused by the hefty penalty, he said.
The fine for dangerous cycling is all part of Spain's shift towards a points-based driving licence.
Spanish drivers receive a total of 12 points but can lose points for various infractions, including talking on a mobile phone while driving, speeding or drink driving.
They can also see points stripped for more unusual activities like reversing on a motorway or throwing any object from a car window that could cause an accident.
But even cyclists can lose points for similar infractions, as Ivan González discovered recently.