Zume, the robotic pizza maker, is now valued at more than US $2 billion, thanks to its latest round of investment. According to The Wall Street Journal, this latest infusion of funds--$375 million--came entirely from SoftBank; and the Japanese conglomerate apparently has another $375 million at the ready should Zume need it. The valuation, in Silicon Valley terms, makes the new company a unicorn, one of the rare breed of startups thought to be worth over $1 billion. Zume, based in Mountain View, Calif., launched three years ago. The company set out to revolutionize pizza delivery by turning pizza-making over to robots, and then cooking the pizza in the back of delivery vans in ovens controlled through cloud-based software.