By Veronika Bondarenko Shake Shack’s summer shake offering is all about the chocolate. Every six months or so, Shake Shack (SHAK) – Get Shake Shack, Inc. Class A Report shakes up its milkshakes and replaces two limited-edition versions on its menu with more seasonal offerings. Since January, the two temporary shakes were the “Chocolate Pie Shake” and the “Wake And Shake.” Made with vanilla custard, coffee, and maple syrup, the latter was the burger chain’s not-so-subtle nod to the cannabis community for a shake that was available during 4/20. And while the effort is an understandable riff on w…