A popular Japanese TV cartoon show in the 70s. Still popular in Japan, with lots of licensed toys and products. Anpanman literally means "Bread Man", and yes, the hero of the show is a cute superman character whose head is a bun. He can save starving children by letting them take a bite out of his head, which is also filled with yummy red bean paste. After a day's adventure, he returns to his base, which is a pastry shop owned by an old baker, who would bake a new head for Anpanman to replaced his partly consumed head. Most of the show characters are "food" people - they have human bodies, but their heads are food with eyes and mouths, etc. Anpanman's nemesis is Bacteria Man.
Anpanman was a TV show created to educate kids in Japan about nutrients and food safety.