Overview: In this episode, Claire Saffitz makes the best oatmeal cookies, the Oat & Pecan Brittle Cookies recipe from her book Dessert Person. This chewy, butterscotchy oat cookie might not be the kind you can casually whip up on a whim. But, if you go through the steps to make it, you will be rewarded with hands-down the most delicious oat cookie you've ever tried.