We can't stop making these. I, too, am sold. Okay, they aren't health food, but using whole wheat flour makes my heart smile.
When making, definitely use the cold butter. When you first mix the cold butter and sugar together, they won't really cream. I still have marble-sized butter lumps until I add the the first egg. Then it all starts to cream together.
No matter how little time you let these puppies bake, you'll get a hard cookie once they cool. We cook them at 16 minutes, eight on the top rack and eight on the bottom, just as Molly suggests. But, honestly, these are best just a bit over done. Something kind of caramelizes and the flavor is fabulous. Try and enjoy!