In a medium sized sauce pot, combine sugar, cornstarch, cocoa powder, and salt. Whisk together until the ingredients are evenly incorporated
½ cup (100g) granulated sugar, ¼ cup (35g) cornstarch, ¼ cup (20g) unsweetened cocoa powder, ¼ teaspoon salt
Gradually add your milk to the dry ingredients, whisking well after each addition to avoid clumps.
2 & ¼ cups (540mL) milk
Place the pot on your stove top set to medium heat. Cook the mixture, whisking constantly, until it comes to a boil and thickens (about 8 to 10 minutes). You'll know the pudding is done when it's thick enough to coat the back of a spoon.
Take the pan off the heat. While the pudding is still warm, add your butter and vanilla. Whisk until the butter melts into the pudding and everything is fully incorporated.
2 tablespoons (30g) unsalted butter, 1 teaspoon pure vanilla extract
Transfer your pudding to a medium sized, heat safe bowl, and cover with plastic wrap pressed against the surface of the pudding (to prevent a skin). Set aside to cool to your liking before enjoying. Pudding can be served warm, at room temperature, or cold.