Zapote negro nieve (25 pesos, about $1.25 at the time), made from the "chocolate pudding fruit."
Nevería Roxy
Av. Fernando Montes de Oca 89 (at Av. Mazatlán), Cuauhtémoc, Condesa, Mexico City
+52 55 5286 1258
(one of many locations)
www.NeveriaRoxy.com.mx
(From a March 2017 visit)