Really?! Is it as simple as that?! I always have this problem - not with the whole batch, but maybe half a dozen will come out with big hollow bumps, almost like bubbles on top. I wish I knew the science behind why your tip would prevent this, but I shall be giving it a go for sure - thanks.
Yes its really that simple! when you roll your dough out on the counter the bottom is much flatter than the top because it has been against the counter (or whatever surface youre rolling on) so when you flip them over they are then smooth side up!