Might be the photo, but it looks to me like top is vanilla cookie with choc-chip, while bottom is chocolate cookie with choc-chip, making it "double" chocolate.

Definitely could be clearer, but I don't think they're making the claim you think they are.

I would assume double chocolate means chocolate dough and chocolate chips. Double in essence, not in quantity. And 40% is referring to how many chocolate chips are in the dough.

Double chocolate if the cookies are chocolate and the chips are chocolate.

It's been this way forever (I'm about 50).

Chocolate chip vs chocolate chocolate chip

Twice as many things have chocolate in it (the chips vs the chips and dough)

I my (extensive) cookie experience, double chocolate usually means the same amount of chips, but the dough part is also chocolate flavoured. Hard to tell in this instance, but the "double" cookies may be a shade darker.

In cookie lingo, double chocolate means the cookie dough is chocolate flavoured as well as having choc chips. Triple chocolate means the chocolate dough with choc chips also has a chocolate coating on the bottom.

unless 40% is caocoa content of the chips.

Does it maybe mean 40% cacao content chocolate?

Bender: “I’m 40% chocolate!”

Double chocolate

I might be stupid, but doesn't "double" mean there's more of it?

So, you're saying maybe 50%?

That's choc-flation for you.

Could also be two different types of chocolate (adding up to the same amount overall). Both packages are 225g, so the overall weight is certainly not doubled.

It's not double chocolate.

It's double choc

Which I'm sure is some marketing weasel word that has nothing to do with chocolate

double choc

Muricans using anything but metric