I found this recipe on jollybartender.com.

blended whiskey (I used Canadian), juice of one lemon, juice of one lime, powdered sugar, grenadine, club soda⁣
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This drink appears in the book Classic Cocktails of the Prohibition Era. It is my first cocktail using powdered sugar, but I’ve noticed that lots of Prohibition-era cocktails use powdered sugar in place of simple syrup.⁣
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This is a dangerous one! The Canadian whisky is so mellow that I can’t taste it at all…all I taste is lemonade. I think this would actually be better with a stronger whiskey flavor.⁣