I recently had someone ask me how to prevent cake pop cracking. Sometimes the chocolate coating develops cracks. This problem can strike random people at random times. It can often seem like there is no pattern at all to the cracking madness. Here are a few tips to try. (If you haven't noticed a problem, then don't mess with a good thing. Keep on doing what you're doing.)
1. Try thinning your chocolate. If its too thick, that could be causing the problem. You can add vegetable oil or paramount crystals. Paramount crystals are hydrogenated palm kernel oil and soy lecithin. It is intended to make chocolate dipping much easier.
2. Don't roll the cake balls too tightly. If you really pack them tight, they will want to expand after the coating is applied, which forces the chocolate to crack.
3. Try a different chocolate. I like to use candy melts for dipping because they have a smoother consistency than chocolate chips but it can be really thick. I have to use a pretty serious bouncing motion to get the excess off. I know there are other brands that work especially well for dipping: Chocoley, Merckens Rainbow Coating, etc. See what you have available or try ordering it online.
4. Freezing the cake pops can sometimes cause this. Some people swear by freezing them, some swear by not chilling them at all. But if you notice cracking, try chilling them in just the refrigerator and avoid the freezer. You might have to experiment for a little while.