This is koshi-an inside black rice "ohagi" rice cakes. The lumpy texture of the black rice and smoothness of the koshi-an is irresistible.
Instead of white rice, use black rice; instead of wrapping with bean paste, wrap with rice. This is a reversed hagi. Everyone I know loves these.
Adding non-glutenous rice and sugar keeps the rice softer longer.If you want the rice darker, use sticky rice, white rice and black rice with a 2:2:6 ratio.Shape while the rice is still warm. Keep the rice scoop in warm water to make it easier to use.
Enjoy Japanese food around the world.