01 - Preheat oven to 350°F. Combine chocolate cookie crumbs, melted butter, and sugar in a bowl until evenly moistened. Press firmly into the bottom and up the sides of a 9-inch pie dish.
02 - Bake crust for 8-10 minutes until set. Remove from oven and allow to cool completely before filling.
03 - Melt chopped chocolate gently using a double boiler or microwave, stirring frequently until completely smooth. Set aside to cool slightly.
04 - Beat room temperature butter and powdered sugar in a large bowl until pale and fluffy, approximately 2 minutes.
05 - Add the melted chocolate and vanilla extract to the butter mixture. Beat until thoroughly incorporated and smooth.
06 - Add eggs one at a time, beating on medium-high speed for 3-4 minutes after each addition. The mixture should become silky, glossy, and significantly voluminous.
07 - Spread the chocolate filling evenly into the completely cooled crust, smoothing the top with a spatula.
08 - Cover the pie and refrigerate for at least 4 hours, or until the filling is completely set and firm.
09 - Just before serving, whip cold heavy cream with powdered sugar and vanilla extract until soft peaks form.
10 - Spread or pipe whipped cream over the chilled pie surface. Garnish with dark chocolate shavings if desired. Slice and serve immediately while cold.