@gap - I've undercooked PDF before and the consistency has been jam-like; and I've overcooked PDF before and it's been a thick, clumpy mess. I can't imagine that it would revert to a jam-like consistency if you kept over-cooking it.
@Elaina - thanks much for the suggestion. I actually have this book and funnily enough I had actually bookmarked the orange PDF recipe with a sticky note. 
I'll try this out, but maybe I'll reduce the amount of sugar a bit (not sure why it calls for more sugar... jam is usually already super-sweet). In your experience how does this turn out? Did you make any changes to the recipe?
