1. William Greenberg Desserts — Upper East Side and Upper West Side, Manhattan
The black and white cookie of record, plus babka and schnecken.
William Greenberg Desserts has been baking in New York for nearly 80 years and is known above all for its black and white cookies, along with babka, schnecken, hamantaschen and butter cookies.
It has shops on Madison Avenue on the Upper East Side and on Amsterdam Avenue on the Upper West Side; Congregation Kehilath Jeshurun lists both as dairy, supervised by Rabbi Mehlman.
Good to know: Buy a box of mini black and whites — they travel well as a gift.
1100 Madison Ave, New York, NY