Bake pie crust according to the directions on the package. Be sure to use a fork to prick holes on the bottom and sides of the frozen pie crust to avoid air pocket bubbles when baking. Set aside.
In a saucepan, stir together sugar and eggs over medium-high heat. Stir constantly so eggs don’t start to bake & whiten. Cook until the temperature of 160°F is reached. Pour the heated mixture into a large bowl so the eggs don’t continue baking in the pan.
In a microwave-safe bowl, melt chocolate in the microwave. Heat on 30-second intervals stirring well after each 30 seconds until chocolate is melted. Don’t overheat – you want this melted but not too hot.
Stir chocolate mixture into egg mixture and stir to mix. Add vanilla and stir to mix.
In a separate medium bowl, combine 1 cup Cool Whip and dry pudding mix together. Set aside.
In a large bowl, beat butter until light & fluffy (about 2-3 minutes). Add chocolate mixture and beat on high speed for 5 minutes. Beat in prepared whipped cream just until combined (don’t over mix).
Pour mixture into prepared pie crust and refrigerate at least 6 hours (or overnight – overnight is best for it to hold its shape when cutting).
Before you serve the pie, top pie with remaining whipped cream. Scoop Cool Whip over top of the pie and sprinkle with coarsely chopped chocolate.