01 - In a saucepan, whisk together sugar, cocoa powder, cornstarch, and salt until evenly blended.
02 - Gradually whisk in whole milk, stirring constantly to achieve a smooth mixture.
03 - Place saucepan over medium heat and whisk continuously until the mixture thickens and begins to boil gently, approximately 5 to 7 minutes.
04 - Remove from heat and stir in chopped dark chocolate and vanilla extract until fully melted and glossy.
05 - Distribute pudding evenly into serving dishes. Cover surface directly with plastic wrap to prevent skin formation.
06 - Refrigerate for a minimum of 2 hours until the pudding is completely set and chilled.
07 - In a chilled bowl, beat cold heavy cream, powdered sugar, and vanilla extract with an electric mixer or whisk until soft peaks form.
08 - Top each pudding serving with a generous spoonful of whipped cream before presenting.