To me, this is the trickiest part about cooking pancakes - getting the pan to the right temperature! If your heat is too low, the pancakes won’t puff up as much, but if it’s too high, they’ll burn and won’t have a chance to bubble up. Always cook the pancakes on medium low, and if you aren’t sure, it’s better to start at a lower temperature and cook just one pancake, then increase (a little bit) if needed.