Preparation

• Sift the cocoa powder, cornstarch, and salt into a medium bowl. With a silicone spatula or whisk, slowly mix in the cream, eliminating any visible lumps as you go; the mixture will be quite thick. Mix in the egg yolks until combined. Set aside.
• Heat the milk and sugar in a 2-quart saucepan over medium heat, stirring often with a wooden spoon or silicone spatula, until the sugar dissolves. When bubbles form around the edge of the milk, remove the pan from the heat. Whisk about half of the hot milk into the cocoa mixture. When smooth, whisk it into the milk remaining in the saucepan.
• Bring the pudding to a boil over medium-high heat, whisking slowly and scraping the bottom of the pot to prevent scorching. The pudding will begin to thicken as it approaches a full boil. Watch for large, lava-like bubbles to roll up to the surface, and for small fast bubbles on the edges. When the pudding has reached this stage, turn the heat down to medium and whisk vigorously for 2 minutes. Remove the pan from the heat.
• Whisk in the vanilla. Transfer the pudding to a shallow container (such as an 8-inch baking dish) and spread it evenly, then press plastic wrap directly onto the surface of the pudding to prevent a skin from forming. Refrigerate for at least 1 hour and up to 3 days.
• Whisk vigorously to loosen the pudding before serving.

Mocha Pudding: Add 2 tsp. instant espresso powder to the pudding when you add the vanilla.
Boozy Chocolate Pudding: Instead of the vanilla, stir in 2 Tbs. of your favorite spirit, such as bourbon, brandy, or Scotch.