Sweet, boozy, and decadent—if ever there was a cocktail made for cold weather and celebratory gatherings, it’s Hot Buttered Rum. “It’s just such a cozy, warm hug of a drink,” says Marco Dionysos, a veteran San Francisco bartender currently at Comstock Saloon. Dionysos has been tweaking his own recipe for two decades. But the roots of the drink itself date back more than two centuries. In Colonial-era New England, the warming mixture provided a rich source of calories. The drink evolved over the decades, albeit slowly. In Jerry Thomas’ 1887 The Bartender’s Guide, the method still involved dissolving a pat of butter directly into the mixture of rum, sugar, spices, and hot water. By 1946, when the cocktail appeared in Trader Vic’s Book of Food & Drink, it was advised that a premade batter of butter creamed with sugar and spices, such as one might use to make a cake, would result in “the finest drink you ever tasted." Whipping up a batter that can be stored and scooped from the freezer is the preferred method today. To solve the persistent problem of a greasy slick atop the beverage, softened ice cream began to be incorporated. This resulted in a more homogenous, creamier drink. Dionysos uses both light and dark demerara sugars, prefers clove oil to ground cloves to avoid any grit, and recently began adding a splash of falernum to up the spice complexity and keep the batter a little softer straight from the freezer. “For me, it’s an essential part of the holidays, and brings back memories with each sip,” says Dionysos. “Also, a bottle of good rum and a container of Hot Buttered Rum batter makes a great gift that keeps on giving."