The milkshake bar at Pi's Kirkwood location goes over the top for all of its creations, from the ice creams exclusively custom-crafted by multiple "Best Ice-Cream Parlor" winner Serendipity Homemade Ice Cream in Webster Groves to the toasted marshmallow atop the s'mores shake. All of the shakes are thick, rich and creamy, and all of the flavor combinations -- vanilla bean, malted chocolate, organic strawberry -- are scrumptious. So what elevates the Peanut-Butter Cookie-Dough Shake above the already lofty bar? We'll tell you what: It's topped with peanut-butter Cap'n Crunch. We're here to tell ya, the sugar rush of nostalgia that's packed into that unexpected sprinkling of crunchy puffed-corn balls with their cloying peanut-ish flavor pushes this shake from a damn-fine gourmet version of a classic to a frickin' Joycean epiphany. Humor, nostalgia, surprise, delivered right to your table. The great shake underneath is a bonus.