Pour the cold water into a small bowl and sprinkle the gelatin on top. Set aside.

Pour the whipping cream, milk, chocolate and sugar into a pot. Sift the cocoa powder and add to the pot. Set the pot to low/medium heat and whisk to combine. Make sure that the mixture does not come to a boil.

Add the gelatin and whisk until fully dissolved.

Pour the liquid into a container with a spout. Set 5 glasses onto a tray and evenly divide the mixture between them. Allow the pudding to cool to room temperature, then cover with plastic wrap and place in the fridge for 4-6 hours, or overnight. In this time, the pudding will divide into layers and will develop an ombre effect, with the darkest colour tasting most chocolate-y. (Note: If you would like the pudding to be a solid colour, place the liquid pudding from step 4 into a bowl and set that bowl over an ice bath. Whisk until the mixture begins to thicken, then pour into the glasses.)

Place the whipped cream and sugar in a bowl and whisk until thick and fluffy. Spoon the cream onto the pudding. Top with dark chocolate shavings and enjoy!