I’ve perfected hot cocoa. I’ve created the cup that I always wanted, but nobody else could give me. All of my life, the cocoa has been too thin and runny—too much like liquid, and I didn’t want liquid. I wanted a dense chocolate cloud in which to lose my sense of direction. To my great joy and greater girth, I finally solved the mystery of how to manifest this vision into reality. My cocoa is as thick as seafoam, yet flows enough to drink, each swallow like a warm hug from inside. The body of this drinkable soufflé comes from whole eggs. I start by following the example of the Viennese, who famously add egg yolk to their cocoa to create a decadently smooth, glossy brown emulsion. But unlike the Austrians, I don’t neglect the whites. Rather, I beat them stiff, then whisk the stiff whites into my cocoa. Unlike …