PERHAPS it's too late to answer but nowadays the are a cake flour that is being sold in Carrefour Argentina. Chacabuco flour special for pastry. > https://harinaschacabuco.com.ar y https://www.carrefour.com.ar/harina-de-trigo-chacabuco-especial-pasteleria-1-kg-695288/pDoes anyone know where I can find cake flour?
BESIDES the are a shop "Cocina con Valentino". on Cabildo Avenue 4047 or Viamonte 758 , BsAs. which sells a lot of flours and another stuff for professional pastry. This is the link https://www.cocinaconvalentino.com.ar
Anyway "Doña Clara" is another shop for professionals. I hope all this can help you.