Name: Chef John's Hot Buttered Rum
Prep time: 15 min
Total time: 15 min
Yield: 6
Ingredients: For the Batter:; 8 tablespoons unsalted butter, at room temperature; ½ cup firmly packed dark brown sugar; ¼ teaspoon pure vanilla extract; ½ teaspoon ground cinnamon; ⅛ teaspoon ground ginger; ¼ teaspoon ground nutmeg; ⅛ teaspoon ground cardamom; 1 pinch ground cloves; 1 pinch salt; For the Drinks:; 6 tablespoons heavy cream; 1 ⅛ cups dark rum; 4 ½ cups boiling water, or as needed; ⅛ teaspoon ground nutmeg, or to taste