Best Way to Create a Text Outline

Hey, what’s the best way to create a text outline (say, for example, 1px black) with a CCLabelBMFont?

I can think of a few ways:
Predraw an outline (by shifting the text 1px in each direction and drawing) on a CCRenderTexture. Downside: lots of extra memory usage
Override CCLabelBMFont to draw an outline with the same method. No extra memory usage, but rendering text takes 4-8x longer.