What Spanish word in common use, which designates a type of pastry, has its origin in the name of the battle where Napoleon Bonaparte was definitively defeated in 1815?

The 'Neapolitan' (chocolate, cream, etc.) does not come from the Italian city of Naples, but from the Battle of Waterloo. In France and Belgium, this bun is called 'pain à la duchesse de Berry' or 'pain viennois', but in Spain it became popular with the name 'Neapolitan'. One theory suggests that it was a euphemistic way of referring to Napoleon's defeat (Napoleon -> Napoleon -> Neapolitan) without directly naming the defeated enemy, although other theories link it to the Italian city.