Cooking the flour in the saucepan cooks out the raw flour flavor, and begins to dry the dough out, so that one
big air bubble forms instead of lots of little ones.
It could be that the batter is undermixed so you're
getting big air bubbles, or they could be puffing up too quickly in the oven and don't have enough structural integrity - a cooler oven might help.
Big air bubbles, crusty exterior, etc..
Gently punch down the dough then remove from bowl and knead between your hands for 1 - 2 minutes, just until you've worked out
the big air bubbles.
They will not allow
a big air bubble to form inside them and possibly tip baby's face down as the air rides up, which is scary.
Lift the pan a few inches above the counter and let it fall, knocking out
any big air bubbles.