Break the chocolate into small pieces. Reserve 8 pieces for garnish.
Place the marshmallows and the milk in a medium saucepan over medium-low heat.
Stir until the marshmallows are completely melted.
Remove the pan from heat and stir in the chocolate.
Stir until all of the chocolate has melted and the mixture is smooth.
Let the chocolate filling cool. This takes about 30 minutes.
Fold in the Cool Whip.
Spoon the chocolate mixture into the Oreo crust.
Spray a piece of plastic wrap with no stick cooking spray and cover the pie.
Refrigerate for at least 4 hours or up to 2 days.
Just before serving garnish with a dollop of Cool Whip and a piece of chocolate.
Notes
Storage: Leftover pie? Promptly cover your no bake chocolate pie with plastic wrap, and place it in the refrigerator for up to 2 days.If you want to make it ahead of time, this pie will freeze beautifully.Tips:
Don't use chocolate chips! They contain stabilizers that prevent them from melting which could result in a lumpy pie. You need classic Hershey bars.
Fold in half the whipped topping and then once it's well mixed fold in the other half. This will keep the whipped topping from deflating.
For easy slicing, run your knife under hot water for about 30 seconds, and be sure to wipe it off after each slice.
A chocolate cookie crust makes this a chocolate lover's dream but you can use a graham crackers crust if you prefer.
Don't fret if the crust crumbles a bit when serving. No bake pies are known to be messy. It's part of their charm!