Scatter 2/3 of the chopped Twix bars on the bottom of the pie crust.
In a small bowl, combine gelatin and cold water. Set aside.
In a large saucepan over medium heat, combine caramels and milk.
Cook until caramels are completely melted and the mixture is smooth.
Whisk in the gelatin mixture.
Pour the caramel mixture into a large heat-proof bowl and place in the refrigerator for 30-45 minutes, until the mixture is tepid, checking it every 10 minutes or so to give a quick stir.
Fold in the whipped topping.
Spoon the caramel cream filling into the pie crust, carefully spreading it over the Twix pieces.
Refrigerate for at least 2 hours, or until pie sets.
In a small saucepan over low heat, combine the milk chocolate chips and heavy cream, and heat until mixture is just melted and smooth.
Allow to cool for 5-10 minutes, or until tepid, and spread evenly over the caramel filling.
Top with remaining Twix pieces as garnish.
Store in refrigerator.
Remove from refrigerator 10-15 minutes before serving so that the Twix pieces can warm up a little. Enjoy!