We just came back from a whirlwind two days in NY, celebrating my mom's 60th birthday. Can't get enough of black and white cookies or Dunkin' Donuts coffee. These black and whites may be the best I've ever had. According to my mom, they are like "cake air'. They came from William Greenberg on the Upper East Side (where you can also custom order your colors) and they are amazing. You can also get them shipped to you if you happen to be unfortunate like me and live somewhere where you can't find black and whites.
I think if someone opened a Dunkin' Donuts franchise in San Francisco, that also sold black and white cookies, they'd make a fortune. From me alone.
ps: Happy Birthday Mom!