Strong Jaw and doubling damage

[Ravingdork]

The strong jaw spells says the following:

If the creature is already Gargantuan or Colossal-sized, double the amount of damage dealt by each of its natural attacks instead.

Does it mean ALL of the damage? Or just the base damage dice?

Say I have a 4d6+15 attack, for example. Does it become (4d6+15)x2, 8d6+15, or 8d6+30?

[Mauril]

RAI is probably that you double the base dice in lieu of upping the die size as normal, but RAW is a bit less clear, it seems. Any of the three could probably be argued, so I'd go with 8d6+15 at my table.

[Archaeik]

You know, I hadn't quite caught that.

I think the intent is to save you having to roll a bucket of dice, because the chart doubles the dice every other increment (but stops at colossal).

So it's roll the dice you have, multiply by 2, then add any bonuses, then account for criticals etc.

RAW, it is poorly worded. Makes me question Pinning KO, which states double your damage result. Slight difference in wording, but I've always taken PKO to mean total damage. Whereas in the context of strong jaw, "damage dealt" almost definitely refers to the "base damage range".