From America's Test Kitchen Season 10: All-Time Cookie Favorites
Thin and crispy oatmeal cookies can be irresistible—crunchy and delicate, these cookies really let the flavor of the oats take center stage. But the usual ingredients that give thick, chewy oatmeal cookies great texture—generous amounts of sugar and butter, a high ratio of oats to flour, a modest amount of leavener, eggs, raisins, and nuts—won’t all fit in a thin, crispy cookie. We wanted to adjust the standard ingredients to create a crispy, delicate cookie in which the simple flavor of buttery oats really stands out.
Given this cookie’s simplicity, creating a rich butter flavor was critical, so we kept almost the same amount of butter as in our standard big, chewy oatmeal cookie, but we scaled back the amount of sugar. Fine-tuning the amount and type of leavener led to a surprising result that solved our texture and shape problems. During baking, large carbon dioxide bubbles created by the baking soda and baking powder (upped from our traditional recipe) caused the cookies to puff up, collapse, and spread out, producing the thin, flat cookies we were looking for. Baking the cookies all the way through until they were fully set and evenly browned from center to edge made them crisp throughout but not tough.
Makes 24 cookies
A dusting of salt atop sweets such as chocolate and caramel is nothing new, but we recently came across Kayak Cookies, which gives a different item the salt treatment: their Salty Oats cookies. After sprinkling a few grains on our Thin and Crispy Oatmeal Cookies, we were hooked. Similar to its effect on caramel, salt's contrasting flavor adds a new dimension to the cookies and accentuates their rich, buttery taste. We prefer the texture and flavor of a coarse-grained sea salt, like Maldon or fleur de sel, but kosher salt can be used. If using kosher salt, reduce the amount sprinkled over the cookies to 1/4 teaspoon.
To ensure that the cookies bake evenly and are crisp throughout, bake them 1 tray at a time. Place them on the baking sheet in 3 rows, with 3 cookies in the outer rows and 2 cookies in the center row. If you reuse a baking sheet, allow the cookies on it to cool at least 15 minutes before transferring them to a wire rack, then reline the sheet with fresh parchment before baking more cookies. We developed this recipe using Quaker Old Fashioned Rolled Oats. Other brands of old-fashioned oats can be substituted but may cause the cookies to spread more. Do not use instant or quick- cooking oats.