Between the Sheets

Between The Sheets
(MacElhorne, 1922)*

1 oz Rum (original calls for Light Rum. Live a little and use whatever you like.)
1 oz Cointreau
1 oz cognac
.5 Lemon Juice

Shake, Strain, Coupe. Garnish: Lemon twist.

This is a variation of the Sidecar cocktail.