PB and Jelly I love to do with the right presentation. I also use a TT to make some things vanish and then have them reappear in a dove pan. I just bought the coloring book and my daughter loves it. I haven't used it at a show yet though. I have found that kids like when you bend forks. I even hand some out and let them try. The more they get to participate, the happier they (and their parents) are going to be.
What do you mean by "the right presentation"? Do mean a routine?
Routine, presentation, whatever you want to call it. If you stand there with the black covers over the PB n Jelly and just lift them up and down, the trick sucks. If you PRESENT the effect to the kiddies in a way that they get to participate a lot, then the trick becomes one of the most fun illusions that you can put into your ROUTINE.