In a medium saucepan, combine sugar, cocoa powder, cornstarch, and salt—give it a good sift and whisk until evenly mixed. This prevents any stubborn pockets of powder.

Pour in about ¼ cup of milk and whisk into a thick paste. Then slowly stream in the rest of the milk while whisking—this keeps lumps at bay.

Set pan over medium heat. Stir constantly (a silicone spatula works wonders) until the mixture bubbles and thickens—about 5–7 minutes. You’ll see the pudding coat the back of your spoon.

Once bubbling, reduce heat to low and cook for 1 more minute, stirring. This step ensures the cornstarch fully activates, giving you that custardy feel.

Take the pan off the stove, stir in vanilla, and whisk until uniform. If you spot any minor lumps, press the pudding through a fine-mesh strainer.

Pour into individual bowls or one large dish. Lay plastic wrap right on the pudding’s surface to avoid a skin layer. Refrigerate at least 1 hour. Top with mini chocolate chips or whipped cream before serving.