Make a Dark and Moody Whiskey Lemonade With Cassis

My bar cart is a crowded, chaotic piece of furniture. At the front, we have the stuff I use on a near-constant basis—gin, Campari, bourbon, and rye—but things get little more esoteric towards the back. As you make your way deeper into my collection of ethanol, you’ll find a lot of liqueurs and amari, including a…