Coffee grounds in milkshakes? Burger joint's secret item sparks frenzy

At most burger joints, dumping coffee grounds in your milkshake would start a fight. But deliciously eccentric burger chain In-N-Out Burger is experimenting with a self-assembled "Frozen Mocha" shake, with growing demands to put it on its infamous secret menu. Here's how it works: You get two-thirds of a chocolate shake and one-third of a vanilla one in separate cups. You also get a little condiment cup full of fresh coffee grounds. Mix them all together, and voila: You’re in fatty frozen caffeine heaven. Someone will read this deep inside Starbucks headquarters, and whisper to themselves: "Mother of God … we're DOOMED." [Source]