In medium sized sauce pan on medium-high heat ,add corn starch, sugar and salt.
Continuously whisk in milk until liquid becomes smooth in texture and comes to a low boil. (make sure to scrape sides and whole bottom with whisk to keep them from burning)
Once you have reached a low boil, turn heat down to medium-low. You may use a spatula to keep scrapping sides and bottom.
Keep stirring until large bubbles just start to come up in mixture.
Remove pudding from heat and stir in the vanilla and butter, adding butter one tablespoon at a time until incorporated.
In a large bowl or into individual serving cups, pour in pudding.
To keep a pudding skin from forming, place plastic wrap directly on top of pudding.
Chill in refrigerator at least 4-6 hours before serving. Recommend chilling over night.
