I’ve made both recipes in cooks illustrated for chocolate chip cookies…and I have had each come out both crispy and chewy. AHHHHHHHHHHHHHHHH! It’s not quite as bad as the cupcake debacle of 2008…but it’s close. As far as I can tell, there are approximately…now let me get this right…about three billion things that will affect the texture of a cookie. If you beat the sugar and the butter together for a long time, you will definitely get a puffier cookie. But, if you don’t bake them long enough, they will flatten down when they cool…and the amount and type of flour seem to be issues, also the type and amount of baking soda/powder combinations, the amount of sugar, and…well…good luck. What I have done, is experiment, make careful notes as to exactly what I have done, and when I’m happy with the cookie, I try to repeat it. So far, I’ve been successful making cookies that I’m happy with, and I’m not as obsessive about them as I am about the cupcakes…but this is going to be a tricky one for you.