Preheat your oven to 350°F (175°C).
Bake the pie crust according to package instructions until golden brown.
Melt the chopped chocolate in a microwave or double boiler, then let it cool slightly.
In a mixing bowl, cream the softened butter and granulated sugar until fluffy.
Add the melted chocolate to the butter mixture and mix until well combined.
Beat in the eggs, one at a time, ensuring each is fully incorporated.
Stir in the vanilla extract, mixing well.
Pour the chocolate filling into the cooled pie crust, smoothing the top.
Refrigerate for at least 4 hours to set the filling.
Whip the heavy cream with powdered sugar until stiff peaks form, then spread over the pie before serving.