Why Does My Chocolate Crack?
Why does my chocolate crack after dipping cake balls with candy melts? The chocolate cracks when drying. WHY?
I'm guessing that your chocolate is cracking because of a change in temperature. Are you trying to get them to set by chilling them?
I'm not very scientific minded, but I remember learning that heat and cold causes expansion and contraction of most objects.
The cake is probably rather moist and then you add the change in temperature and cracking chocolate may be the result.
Try allowing the chocolate to set at room temperature (or an air conditioned room if it's a particularly hot day.
If your situation doesn't allow for a cool enough environment and you feel you must refrigerate or chill your chocolate covered cake balls, only put them in for 5-10 minutes and see if you can get them to harden without getting too cold and cracking.
Hope that helps some. I'm starting to drool just thinking about biting into one of your cake balls! :)