For a quick and easy cocktail, nothing beats a sugar cube trio. This simple recipe requires just three ingredients: sugar cubes, bitters, and water.

To make the sugar cubes, combine sugar and water in a saucepan over medium heat. Stir until the sugar has dissolved, then pour the mixture into a silicone ice cube tray. Freeze for several hours, then pop the cubes out and store in a sealed container.

For each drink, place one sugar cube in a glass …