For the crust

1. On a floured work surface, roll out the disc of chilled dough to fit a 9-inch pie dish.  Rotate the dough 90° after every few rolls.  You should have an approximately 12-inch circle in diameter of dough.  Carefully transfer the dough into your pie dish.  Using kitchen shears, trim the excess dough around the edges, leaving just enough to fold under the edge of the dough for a thick crust.  Using your fingers, flute the edges of the crust.  Refrigerate your crust in the dish for at least 30 minutes.
2. Preheat oven to 400°F/204°C. Line the inside of the crust with a piece of parchment paper and add pie weights*.  Spread the weights evenly within the pie dish.
3. Bake the pie crust for 15 minutes. Take the crust out of the oven.  Remove the pie weights, prick the bottom of the crust with a fork, and brush the edges with egg wash.  Return the crust to the oven and continue baking for an additional 12-15 minutes or until golden brown.
4. Allow the pie crust to come to room temperature.

For the filling

1. In a medium heatproof bowl, add your chocolate.  Place over a small saucepan filled with an inch of boiling water and stir until melted.  Set aside.
2. In another medium heatproof bowl, whisk together the sugar and the eggs.  Set over a small saucepan filled with an inch of simmering water.  Whisk constantly until the egg mixture reaches 160°F/71°C, about 10 minutes.  Remove from the heat, allow to cool slightly, and then stir in the melted chocolate and vanilla until smooth.  Set aside to cool until just warm, stirring occasionally.
3. Using a hand mixer or stand mixer fitted with the paddle attachment beat the butter on medium-high speed until light and creamy, about 2 minutes.  Slowly add in the cooled chocolate mixture and then increase speed to high and beat for about 5 minutes or until light and fluffy.  Occasionally, scrape down the bottom and sides of the bowl to ensure everything is evenly mixed.
4. In a clean bowl using a hand mixer or stand mixer fitted with the whisk attachment, beat the cream and powdered sugar on medium-high until stiff peaks form.  Carefully fold this whipped cream into the chocolate mixture.
5. Pour the chocolate mixture into your prepared pie crust.  Using an offset spatula spread the filling evenly.  Cover with plastic wrap and chill in the refrigerator for at least 4 hours or overnight to thicken.

For the topping

1. In a large bowl using a hand-held mixer or stand mixer with the whisk attachment, whisk the heavy cream, powdered sugar, and vanilla on medium-low speed until mixture becomes frothy.  Increase speed to medium-high and continue whisking until medium peaks form about 3 minutes.  Careful not to over mix or else it will become thick and lumpy.
2. Spread the whipped cream over the chilled chocolate filling.  Sprinkle with chocolate shavings, if desired.  Serve immediately.