Unlike with my almond and pistachio croissant cookies, key lime pie cookie recipes do exist in some form on the internet and I’m pretty sure Crumbl had a version of these, too. BUT, all of those versions are fake key lime pie cookies. What do I mean by fake? They’re a graham cracker cookie with a key lime pie-flavored frosting spread on top after baking, often made with cream cheese. Yuk! If I’m going to have a key lime pie in cookie form, I want it to be as close to the original as possible, which means baking the filling. The type of cookie most eligible to handle such a task: the humble thumb print. Usually, teeny tiny and crumbly, thumb print cookies are forgettable. When you make them absolutely massive as I do here, and ensure the cookie stays moist through a quick bake time, they become sensational.