In a pot mix the milk, water, sugar and spices (crush and dehusk the cardamom, adding only the seeds), and gently heat over low to medium heat until just below boiling.
Remove from the heat and mix in the cocoa powder, and vanilla. Return to low heat for 1 minute stirring constantly.
Remove from the heat and discard the cinnamon and bay. Next, add in the dark chocolate (you can use anything from 55% to 80% for this depending on taste) and stir off the heat until melted. Finish with a small pinch of sea salt.
Emulsify with a handheld blender and divide into 2 mugs. Top with whipped double cream and a grating of dark chocolate.