I like roselle (or hibiscus) and the Taiwanese pineapple cakes, this combination sounded great (and a welcome surprise from my beautiful Bride). The roselle in the cake is jam made from roselle juice with wax gourd.
I would be very generous in saying that this tastes a lot like the roselle I like, the excellent sourness it has. The roselle jam is quite subtle, but not bad. An interesting idea, but not well delivered.