From the Times story by David Leite:
At 12 hours, the dough had become drier and the baked cookies had a pleasant, if not slightly pale, complexion. The 24-hour mark is where things started getting interesting. The cookies browned more evenly and looked like handsomer, more tanned older brothers of the younger batch. The biggest difference, though, was flavor. The second batch was richer, with more bass notes of caramel and hints of toffee.Now, Ideas in Food:
Going the full distance seemed to have the greatest impact. At 36 hours, the dough was significantly drier than the 12-hour batch; it crumbled a bit when poked but held together well when shaped. These cookies baked up the most evenly and were a deeper shade of brown than their predecessors. Surprisingly, they had an even richer, more sophisticated taste, with stronger toffee hints and a definite brown sugar presence. At an informal tasting, made up of a panel of self-described chipper fanatics, these mature cookies won, hands down.
The second insight Mr. Rubin offered had to do with size. His cookies are six-inch affairs because he believes that their larger size allows for three distinct textures. “First there’s the crunchy outside inch or so,” he said. A nibble revealed a crackle to the bite and a distinct flavor of butter and caramel. “Then there’s the center, which is soft.” A bull’s-eye the size of a half-dollar yielded easily.
What I can tell you is that the dough darkened and became fully saturated, similar to the way that the dough usually looks after a couple of days in the refrigerator. It also changed the texture of the dough, making it a bit more elastic to the touch. The just made dough was too soft to shape and needed to chill, so I left in the fridge for about three hours before baking.Link (via MeFi)
The resulting cookies were pretty damn good. They had a slightly cakey texture in the center with chewy yet crisp edges and rich buttery, caramel flavors. It was impossible to eat just one and I was thankful that I had not baked off the entire batch.