Do not make this recipe until you are ready to assemble the chocolate chip cake. Once it is cold, coffee frosting is hell to bring back up to room temp. It will separate on you, and you will spend the same amount of time trying to force the coffee milk back into the butter mixture.

　　

Ingredients

Makes about 200 g (1 cup)

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

　　40 g confectioners’ sugar (1/4 cup)

　　55 g milk (1/4 cup)

　　1.5 g instant coffee powder (3/4 teaspoon)

　　1 g kosher salt (1/4 teaspoon)

　　

Step 1

Combine the butter and confectioners’ sugar 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.

　　

Step 2

Meanwhile, make a quick coffee milk: whisk together the milk, instant coffee, and salt in a small bowl.

　　

Step 3

Scrape down the sides of the bowl with a spatula. On low speed, gradually stream in the coffee milk. You are essentially forcing liquid into fat, so be patient. The butter mixture will clump up and separate upon contact with the coffee milk. Do not stream more coffee milk into the butter mixture until the previous addition is fully incorporated; keep the mixer on and remain patient. The result will be a wildly fluffy coffee frosting, pale brown and super-shiny. Use immediately.

　　

Notes

Step 4

We use Nescafé instant coffee for this delicious frosting. The entire country of Greece makes an amazing frappe that puts Starbucks’ frappuccino to shame, and Nescafé is the secret ingredient.

　　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.