Unfortunately, I haven't found early citations.
29 November 1979, Washington (DC) Post, "Anne's Reader Exchange," pg. E23:
13 May 1998, New York (NY) Times, "Look to the Cookie: An Ode in Black and White" by William Grimes, pg. F1:
The black-and-white has been around forever. Herb Glaser, the baker at Glaser Bake Shop on First Avenue near 87th Street, said that as far as he knew, Glaser's has been making them ever since it opened 96 years ago. "When I was growing up, I'd have two of them for dessert every day," Mr Glaser said. "I was a fat kid."
Technically, the black-and-white is not a cookie but a drop cake. The batter resembles the batter for a cupcake, with a little extra flour so that the dough does not run all over the place when it is dropped, dollop by dollop, on the baking cheet. "The trick is to add enough flour so the batter holds a shape, but not so much that the cookie becomes dry, which is a common problem with the black-and-white," Mr. Glaser said. Once baked, it is iced with chocolate and vanilla fondant frosting.
4 August 1999, New York (NY) Times, pg. F2:
What's Black and White and New York as Seinfeld?
by Florence Fabricant
28 January 2001, New York (NY) Times, "Smart Cookies: Why black-and-whites have assumed deep cultural significance" by Molly O'Neill, pg. SM39:
The black-and-white, that frumpy and oversize mainstay of New York City bakeries and delis, has not endured by dint of its taste. Unlike other edible icons, like New York cheesecake or bagels, there is no such thing as a delicious black-and-white cookied. They are either edible or inedible. Fresh-baked and home-baked are the best.
(Pg. 50 -- ed.)
Outside New York, cookies with black-and-white icing are cookies with black-and-white icing. In Boston, where they are called half-moons, and in the Midwest, where they are known as harlequins, they are considered ordinary and have been around, say most bakers, "forever."
A comment from a boy who grew up in The Catskills: in my opinion, Katz’s Bakery in Liberty had the best Black & White cookies.
I remember going in as a child with my mother and Old Mrs. Katz (as everyone called her) would give me a large piece from the broken cookies. This was practically a miracle since Old Mrs. Katz was quite a grouch and curmudgeon!
barry i can add that the black&white cookie was known as the ‘modernistic’ cookie around cleveland. a twist is the cookie itself was black&white. sometimes it had the frosting, sometimes not. i’m not sure you can find them around there anymore.
fantastic. The great b&w quest is long and arduous. been obsessed since the ‘60s in wash hts--alpine’s on dyckman st., german-jewish bakery on 181st, both defunct--now transplanted to iowa. nothing local of course; struggling to find even a half-decent mail-order facsimile. have basically given up on good; will settle for alright.
despite multiple claims of authenticity, the b&w’s in chicago all bite the humungous/ginormous one, mostly frozen in bklyn, shipped, defrosted, and dry, dry, dry. or else just lame.
know it’s not yr mainline, but i’m dyin’ for 7-layer cake, old-style soft. like w/ b&w’s, most mail orders just repackage and/or freeze the same hard-ass brooklyn bakery’s.
anyway, keep fighting the good fight; every bite you take you take for others less fortunate. deprived of b&w oral, the glossies & details are hottest action we get. thank you!
p.s.: you can do a whole psychology on how a person indulges. yes, the chocolate after the vanilla, but the half&half row down the middle last & best!
barry i can add that the black&white cookie was known as the ‘modernistic’ cookie around cleveland. a twist is the cookie itself was black&white. sometimes it had the frosting, sometimes not. i’m not sure you can find them around there anymore…
thanks for great answer..