I just fixed it with a pretty simple hack, though not ideal will do the trick for now. Create your label with the font at x2 size and then scale the label to 0.5 to get it back to its normal size. See my screenshot for the before and after results.
You could create with larger sizes (and scale back down appropriately) but remember larger sizes will create labels that take more memory as they render larger to textures, along with this note that the size of the label is limited depending on the device, see [[http://www.cocos2d-x.org/wiki/Max_size_of_textures_in_cocos2d-x_depends_on_each_platform]]
myLabel = CCLabelTTF::create("Play", "Helvetica", 20*2, CCSizeMake(0, 0), kCCTextAlignmentCenter);
Edit: formatting for clarity, reduced scale to 2 for memory and label rendering size concerns