The Maple Leaf is a simple riff on the classic Whiskey Sour template, but it’s delicious enough to merit its own entry in Cocktail Party.
We like using Grade B maple syrup in our drinks. It’s darker, with a stronger maple flavor that comes through in a stiff drink.
Whatever you do, just make sure you have a true maple syrup, rather than a maple-flavored corn syrup (as is regrettably commonplace in the US).