Pikelets, just like waffles, need a raising agent to help make them light and bubbly. And that is why self-raising flour is used for them. One disadvantage, however, is that self-raising flour starts into action as soon as it becomes wet, so the batter must be used immediately.
If self-raising flour batter is left to stand, the bubbles escape and the results will be heavier instead of a lighter pancake. So the secret is to make the batter just before you make the pikelets.
** Asian Online Recipes