puffed cereal; puffed grain snack
Refers to grains (often rice, wheat, or corn) that have been puffed under high pressure, commonly sold as a light, crunchy snack. The term is especially associated with traditional street vendors who make it with a loud popping sound.
When I was a child, I was bought puffed cereal at the festival.
Puffed cereal is made by expanding rice in a pressure cooker.
ポン is an onomatopoeia for the popping sound made during the puffing process, and 菓子 means 'confectionery' or 'snack'. The exact origin of the term is uncertain, but it likely emerged from street vendor culture in the early 20th century.