Quick Chocolate-Peanut Butter Pudding

This is a recipe that my parents used to make for me and my sisters, and that I still make now. I just made some last night, so I thought I'd share it with you guys.
The recipe is from an old-school cookbook called The More With Less Cookbook.

Original Recipe:
1/3 cup white sugar
2 tbsp Cornstarch
2 tbsp Cocoa - Dry powder, unsweetened
2 cups Milk ( I use 2%)
1 tsp Vanilla extract
2 tbsp butter (or margarine)

Instructions:
In a saucepan, heat all the ingredients except for the butter on medium heat, stirring frequently. You need to keep an eye on this or it will scorch and you'll be sad. When the mixture has started to bubble, add the butter/margarine, and reduce the heat. Keep stirring until it's thickened. Let cool to at least room temperature. It can be eaten warm or cold-it thickens more the cooler it gets.
Serves 4.

The Chocolate-Peanut Butter Variation (the only True Way to eat this):
Replace the butter/margarine with 1/4 cup peanut butter. I use Kraft. Proceed as usual, and try not to eat all 4 servings at once.

The Party-In-Your-Mouth Double Chocolate-Peanut Butter Variation:
Use chocolate milk in place of white milk. Eat entire batch right of the pot, scalding your mouth in the process.

Here are the facts (based on the choco-PB version):


Notes:
-If you don't have cornstarch, the same amount of flour can be used, but the pudding will take longer to get pudding-y.
-You can use almond, coconut, soy, etc., milk in substitute for this, but the resulting taste/texture will not be the same.

Enjoy!