6 large egg yolks
1/2 cup plus 3 tablespoons sugar
1/4 cup cornstarch
3 tablespoons high quality cocoa powder
1/4 teaspoon instant coffee or instant espresso powder
1/8 teaspoon salt
2 cups whole milk
1/3 cup semi sweet chocolate, chopped
2 tablespoons unsalted butter
3 tablespoons heavy cream
2 tablespoons pure vanilla extract
Combine the milk, salt and coffee powder in a saucepan and cook it over medium heat until it comes to a simmer.
Whisk the egg yolks, sugar and cream until thick. Add the cornstarch and cocoa powder and whisk very well to combine.
Slowly pour a cup of the hot milk into the chocolate and egg yolk mixture to raise the temperature (temper) and whisk it well. Add some more milk and then pour the entire mixture back into the saucepan.
Cook over low heat, whisking constantly until thickened. This will happen in a few minutes so Do Not Step Away from the saucepan!! Once thickened, it will resemble the thickness of mayonnaise.
Remove from the heat and add chocolate, butter and vanilla extract. Whisk well until the chocolate and butter are completely melted and the mixture is smooth.
Pour into serving bowls or into one big bowl and cover with plastic wrap.
Allow the pudding to chill 4 hours or overnight.