Zim, where did you get the palm sugar? Is it the bottled stuff (with the layer of wax atop)?
I normally break it up (all of it) into more manageable chunks and then store. Quick microwaving helps soften the palm sugar. This would vary on the palm sugar <sup>1</sup>. Ideally it shouldn't be too hard <sup>2</sup>. As CG & JeffB suggest and I recently came across – the tubs of palm sugar at Thai Grocer (IIRC $1.95) are excellent. It is soft and wonderfully fragrant and a much deeper brown than the bottled stuff. I was told that this jaggery was fresh and portioned out from much larger vats.
Have you considered using palm syrup (also)?
1. Palm sugar or candy is made by boiling down the sap/syrup from the (toddy) palm – much like maple syrup and candy.
2. I had some palm sugar (Indian) that I stored in my freezer – and it still stayed pliable. This 'jaggery' or (notun) gur is a different beast/quality altogether.
This is may also be of interest -
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JoelF wrote:For piloncillo (Mexican brown sugar "cones") I usually use a grater.
I think these are from cane sugar. I know in India that there are two types of 'jaggery' or
gur- from sugar cane (for which I use piloncillo) and from the (toddy) palm.
edit:
A webpage on different sugars