Combine all ingredients except butter in a large microwaveable bowl.Microwave for 2 minutes, and then stir. Continue microwaving for 1-2 min until pudding has thickened.
Pour the pudding into bowls, mason jars, or dessert dishes for serving.Refrigerate for 2 hours to serve cold, or let chill in the refrigerator for 10-15 minutes to serve warm.