Jensen Huang's five-layer cake goes up twice in Stanford's MS&E 435, and both times the guest gets the same question: you have $100, which layer do you put it on? I worked through all 9 in August 2026. The shape underneath them: semiconductors took 79% of AI gross profit in 2026 and applications took 7%, the inverse of cloud software. This recap walks the course in order, from $59M per megawatt to a 16% antibody hit rate, and argues that "compute is scarce" has become the industry's substitute for a depreciation estimate. Nine lectures, and the number that decides whether any of it pays never appears on a slide.