(And, and P.S., these are enormous. They were for Mark's birthday party and he didn't want him any tiny Mommy-style cookies.)
I'd all but given up on chocolate chip cookies made from all butter. They just never turned out as well as their part-shortening brothers (which are, for the record, shockingly delicious). The problem with the all-butter cookies was their texture--the cookies came out sort of airy (for lack of a better word). They weren't as dense as the part-shortening counterparts. Also, the tended to come out a little flatter (by which I don't exactly mean flatter, but without the shape that dense cookies have--those folds of dough that just seem to sit there after the cookie has cooled), and they would dry out much more quickly (airy--like I said). It didn't matter if the butter was cold or fully melted. It didn't matter if we beat the sugar in or mixed it by hand. Resting the dough helped, but not enough to make for a perfect, dense, chewy cookie. Nothing seemed to matter and I gave up. And then all the sudden, Kip's all-butter cookies just started to come out right. Every single time. The difference? He started rolling them into balls before baking (also, he got the butter super softened, but not melted--which I do think is helpful as well, though we've occasionally accidentally melted it and the cookies still come out okay if we roll them). I thought this was too easy to be an answer. But it's been several months now and every time we roll the cookie dough before baking, they come out RIGHT.
Hopefully my photography is good enough for you to see the difference between these cookies (you've got to look kind of close).
from un-rolled dough plops
from rolled dough balls
The one on the bottom was rolled; the one on the top was not. Both were from the same batch and baked at the same time. But you'll notice that they rolled one (bottom) has fewer airy-type holes. Also, the non-rolled one (top) almost seems to have its top layer sort of disconnected by air from the rest of the cookie. Also, the non-rolled one (top) is somewhat flatter.
I assume that the process of rolling the dough into balls simply compresses all that cookie goodness and sort of sticks the ingredients together better than they otherwise would have been. How's that for scientific talk?
So if chocolate chip bliss is alluding you, try rolling the dough before baking. You might be surprised.