Ingredients

makes about 1 quarter sheet pan

　　115 g butter, at room temperature 8 tablespoons (1 stick)

　　75 g light brown sugar 1/3 cup tightly packed

　　40 g granulated sugar 3 tablespoons

　　1 egg yolk

　　80 g flour 1/2 cup

　　120 g old-fashioned rolled oats 1 1/2 cups

　　0.5 g baking powder 1/8 teaspoon

　　0.25 g baking soda pinch

　　2 g kosher salt 1/2 teaspoon

　　Pam or other nonstick cooking spray (optional)

　　

Step 1

Heat the oven to 350°F.

　　

Step 2

Combine the butter and sugars in the bowl of a stand mixer fitted with the paddle attachment and cream together on medium-high for 2 to 3 minutes, until fluffy and pale yellow in color. Scrape down the sides of the bowl with a spatula. On low speed, add the egg yolk and increase the speed to medium-high and beat for 1 to 2 minutes, until the sugar granules fully dissolve and the mixture is a pale white.

　　

Step 3

On low speed, add the flour, oats, baking powder, baking soda, and salt. Mix for a minute, until your dough comes together and any remnants of dry ingredients have been incorporated. The dough will be a slightly fluffy, fatty mixture in comparison to your average cookie dough. Scrape down the sides of the bowl.

　　

Step 4

Pam-spray a quarter sheet pan and line with parchment, or just line the pan with a Silpat. Plop the cookie dough in the center of the pan and, with a spatula, spread it out until it is 1/4 inch thick. The dough won’t end up covering the entire pan; this is OK.

　　

Step 5

Bake for 15 minutes, or until it resembles an oatmeal cookie—caramelized on top and puffed slightly but set firmly. Cool completely before using. Wrapped well in plastic, the oat cookie will keep fresh in the fridge for up to 1 week.

　　Reprinted with permission from Momofuku Milk Bar by Christina Tosi with Courtney McBroom. Copyright © 2011 by MomoMilk, LLC. Published by Clarkson Potter, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.Christina Tosi is the chef and owner of Momofuku Milk Bar, called "one of the most exciting bakeries in the country" by Bon Appètit. As founder of the desserts programs at Momofuku, including Noodle Bar, Ssäat;m Bar, Ko and Má Pêche, Christina was most recently shortlisted for a James Beard Foundation Rising Star Chef Award. Christina and her confections have appeared on The Martha Stewart Show and Live! with Regis and Kelly, among others. She lives in Brooklyn, New York, with her three dogs and eats an unconscionable amount of raw cookie dough every day.