[11] Chang hired Tosi to create the plan, then eventually to do other administrative work and liaise with the NYC Department of Health.

[17][7] There were no desserts on Chang's menu when Tosi came on board,[4] and she created her own pastries inspired by the flavors of childhood favorites, developing recipes such as Cereal Milk-flavored panna cotta.

[15] Tosi's approach was to use pastry chef techniques to create comfort-food influenced desserts served in a casual setting.

[17] In 2017 Ben & Jerry's introduced a line of flavors that Eater called a [blatant ripoff] of Tosi's Cereal Milk.

[21] According to the New York Times in 2021, "Nothing bears the trademark of the pastry chef Christina Tosi more than her cereal milk flavor.

[23] Axios in 2022 called Tosi's cereal milk and crack pie creations "cult favorites".

[24] Francis Fabricant said Tosi "made Cereal Milk soft-serve and the Compost Cookie household names".

Tosi's Momofuku Milk Bar (2011), a cookbook containing recipes from the restaurant, was published by Clarkson Potter.

[29] Washington Post reviewer Chang said "There’s something intellectually provocative about 'Milk Bar Life,' with its mad juxtapositions of Fruity Pebbles and slow-simmered sauces", but that "after the chemical party in your mouth subsides, you might just find yourself longing for a poached pear".

[27] Jenny Rosenstrach of the New York Times Book Review wrote of her second book, "It's impossible not to be charmed by the chatty Tosi and her hot pink and bubble-letter-filled never-never land..."[30] Tosi's Dessert Can Save the World (2022) was described by Publishers Weekly as a "clumpy mix of memoir and self-help", saying that "Despite the delicious premise, the filling leaves much to be desired.

[39] Tosi has made advertising appearances for Subaru,[40] American Express, Kellogg's, Estée Lauder,[41] and Verizon.

[47][37] The New York Times describes Tosi as "an introvert in overalls who carries math problems in her purse, along with embroidery thread to make friendship bracelets".

[12][8] On July 30, 2016, Tosi married New York City-based restaurateur Will Guidara, co-owner of Eleven Madison Park.