Ingredients: 1 1/2 oz bourbon, 1 oz simple or flavored syrup, 1/2 oz lemon juice. Shake with ice and strain into a glass; top with about 2 oz club soda.
Source: DIY Cocktails
A fizz is basically a Collins, but shaken instead of built. Honestly, shaking is kind of a pain in the ass. I’m sick of fizzes. :p