In a medium saucepan, pour in 2 cups of your chosen milk and add 1 heaping 1/8 teaspoon of salt, along with 1/4 cup of Dutch cocoa powder and 1/3 cup of your preferred sweetener. Heat the mixture over medium heat, stirring gently until it becomes warm but not boiling, approximately 3-5 minutes.

In a separate bowl, whisk together 3 tablespoons of cornstarch with 1/2 cup of the warm milk mixture from the saucepan until fully dissolved and homogeneous.

Once the milk mixture is warm, gradually whisk in the cornstarch mixture while stirring constantly. Increase heat to medium-high and bring the pudding to a gentle boil, stirring continuously for about 2 minutes until it thickens noticeably.

Reduce the heat to low and let it simmer for an additional minute. Remove from heat, stir in 3/4 teaspoon of vanilla extract and the optional 3 ounces of chocolate until fully melted and combined.

Transfer the pudding into individual serving bowls or a single dish and allow it to cool to room temperature. Cover with plastic wrap, pressing it directly onto the surface to prevent a skin from forming, and refrigerate for at least 2 hours or overnight.