El Bar Americano en España by Pedro Chicote (1927, p.137)

1 tablespoonazúcar en polvo — 1 cucharada de azúcar en polvobase
1 copitaFine Champagne (coñac) — 1 copita de Fine Champagne (coñac)base
agua hirviendo — Used to fill the glass.dilution
1 slicerodaja de limón — 1 rodaja de limóngarnish
nuez moscada rallada — Added after filling.other
  1. Prepare the same way as the Scotch sling, replacing the whisky with a copita of Fine Champagne cognac.

Defined by Chicote as the same preparation as the hot Scotch sling with cognac in place of whisky.