锅巴 originally meant the crunchy golden rice crust scraped off a wok or pot - a prized leftover, especially in Sichuan and Jiangsu cuisine where it is poured over with hot soup or sauce (
锅巴肉片). The packaged snack version, sold in supermarkets, became popular in the 1980s.
巴 here means 'something stuck-on'.
