01 -
In a medium saucepan off heat, whisk together sugar, cocoa powder, cornstarch, and salt until uniform and lump-free.
02 -
Gradually whisk in whole milk and heavy cream until mixture is fully blended and smooth.
03 -
Place the saucepan over medium heat and cook, whisking constantly, until thickened and bubbling, approximately 5 to 8 minutes.
04 -
Remove from heat, then stir in chopped dark chocolate and butter until melted and pudding is glossy.
05 -
Mix in vanilla extract thoroughly.
06 -
For an extra smooth texture, pass the pudding through a fine mesh sieve into a serving bowl.
07 -
Cover surface directly with plastic wrap to prevent skin formation; chill for at least 2 hours before serving.