Poi is pounded taro root — a Native Hawaiian staple, mildly tangy, purple-gray, traditionally eaten plain alongside savory food rather than as a dessert. Poi mochi took that same poi and folded it into a mochiko batter that gets fried into golf-ball-sized nuggets: crisp and craggy outside, dense and chewy inside, with a faint tang and that characteristic pale-purple tint running through.
It's a bakery-case and potluck regular precisely because it's forgiving — the dough comes together in one bowl, and the balls fry up fast.