Place pieces of chocolate into the bottom of a blender.
Place egg yolks, sugar, vanilla extract, salt, milk and cream into a medium sized saucepan and whisk briefly to combine.
Place over a medium heat and bring to a gentle boil, stirring frequently.
Once the mixture is gently bubbling away, turn the heat down to low and stir gently until the mixture is thickened enough to coat the back of a spoon.
Remove from the heat and pour over the chocolate in the blender.
Pulse the mixture until completely smooth and thick. Make sure there are no lumps of chocolate.
Spray two 6oz ramekins lightly with cooking spray and then divide the chocolate mixture between the ramekins. Leave to cool for 30 minutes and then place in the fridge for 2-2 1/2 hours, or until fully set.
Serve with a dollop of whipped cream and grate some chocolate on top, if desired.
Chocolate Pots de Creme are best eaten on the day you make them, but will keep in the fridge, covered, for one day.