Over a medium bowl sift, a 1/2 cup of sugar with the unsweetened cocoa powder, cornstarch and salt.

Whisk in 1/2 cup of the milk to make a smooth paste. Scrape the bottom of the bowl with a rubber spatula to be sure that everything is well mixed.

Add the chopped chocolate to a medium sized bowl(make sure to use a heat proof bowl).

In a medium saucepan combine the heavy cream with the remaining 11/2 cups of milk and 1/4 cup of the sugar, bring to just a simmer over moderately high heat.

Reduce the heat to medium-low heat and stir in the cocoa paste.

Whisking constantly, boil the mixture for 1 minute. Pour the mixture over the chopped chocolate in the bowl.

Add the vanilla and stir until the pudding is smooth.

Pour the pudding into small dessert dishes, ramekins, or 6 small glasses. Alternately you can just pour it all in one bowl and serve from there.

Cover the top of pudding with a piece of plastic wrap and refrigerate until set, at least 4 hours or overnight.

To make the whipped cream garnish:

Add the cold heavy cream and the confectioners sugar to a bowl and whip with an electric mixer or a whisk until soft peaks form, then add vanilla extract and stir until just combines