In a small saucepan, set over medium-low heat milk, whisk together milk, cocoa powder, sugar, vanilla and salt.*Alternatively, heat milk, cocoa powder, sugar, vanilla and salt in a micro-wave safe cup on High, stirring every 30 seconds for 60 to 90 seconds, or until steaming.
Cook, stirring often, for 3 to 5 minutes or until steaming, whisk with a frother or hand blender until frothy.