levain bakery cookies
I have found that a critical technique for achieving the texture of the Levain Chocolate Chip/Nut cookie is to make the cookie dough, then let it "rest" in the fridge for 24-48 hours before baking it. I've had luck getting the gooey center by setting the oven to 375 F then dropping the temp to about 330 F a few minutes after the dough goes in the oven. Also, I use Plugra in lieu of the average grocery mart butter.
re: Non Cognomina
Plugra is a high-milk-fat butter (82% milk fat) made in the US in the "European Style."
If you are in NYC, you can get Plugra at Trader Joe's in Union Square, or at any of the Whole Foods Markets (where you'll pay twice as much as at TJ's).
itryalot, if you are in Canada, you may find this thread helpful:
I use a non-convection setting at home. If you have a convection oven, use initial temps of 347F/175C, then drop to 302F/150C to finish with fan on low.
I've been wanting to try these, but not had time. Let me know how it works for you.