Creating a new cocktail doesn’t happen every night behind the bar, no matter how good the bartender. Sometimes they’re happy accidents, sometimes they’re deliberate attempts that take weeks to perfect. Yet every cocktail bartender I know has this moment, at least once per evening, where someone walks in with a stump-the-bartender request. Just yesterday, a guest asked me to whip up a new cocktail using tequila and pear eau de vie. I was, to be honest, completely flustered. It went against how you’d normally construct construct a good drink.

Most cocktails don’t contain two spirits. It’s just not part of the formula, typically. Classic cocktails are most often composed of a base spirit and a series of modifiers. A Manhattan, for instance, uses rye whiskey as its base spirit, with vermouth as a secondary component and bitters as a modifier. A Daiquiri uses rum as its base spirit, lime as a sour component, and sugar as a sweetener. That’s the general rule: One spirit, not two.

So when I was presented with this challenge of using two base spirits in a cocktail, I reached for the only formula I knew off the top of my head that calls for two base spirits, and that’s the classic two-spirit cocktail, Between the Sheets.

At first glance, the recipe for a Between the Sheets is a bit of a mess. Containing equal parts Cognac and aged rum, with lemon juice as a sour component and Cointreau as a sweetener, it doesn’t make a whole lot of sense. But upon closer examination, the Between the Sheets is nothing more than a Sidecar, whose base spirit has been split into two halves; instead of two parts Cognac, the Between the Sheets uses one part Cognac and one part aged rum.

As much as I love a Sidecar (after all, it is one of the first classic cocktails I set out to master) I really do appreciate a good Between the Sheets. Cognac’s refined, regal flavors are tempered by feisty Caribbean rum, like a pirate plundering a French chateau. It’s a little lighter than a Sidecar, which is just right for this post-holiday time of year.

Between the Sheets
¾ oz. Cognac
¾ oz. aged rum
1 oz. Cointreau
¾ oz. lemon juice
1 tsp. 2:1 simple syrup

Combine ingredients in a cocktail shaker and shake with ice until well chilled. Strain into a cocktail glass and garnish with an orange twist.

Jeffrey Morgenthaler is the bar manager at Pépé le Moko and Clyde Common, the acclaimed gastropub at the Ace Hotel in Portland, Oregon. He is also author of The Bar Book: Elements of Cocktail Technique.