01 - Preheat oven to 350°F.
02 - Combine chocolate cookie crumbs, melted butter, and sugar in a bowl. Press firmly into bottom and up sides of 9-inch pie dish.
03 - Bake for 8-10 minutes. Allow to cool completely before filling.
04 - Melt chocolate using double boiler or microwave, stirring until smooth. Cool slightly.
05 - Beat butter and powdered sugar in large bowl until pale and fluffy, approximately 2 minutes.
06 - Add melted chocolate and vanilla extract. Beat until thoroughly incorporated.
07 - Add eggs one at a time, beating on medium-high speed for 3-4 minutes after each addition until silky and glossy.
08 - Spread chocolate filling evenly into cooled crust.
09 - Cover and refrigerate minimum 4 hours or until completely set.
10 - Whip cream with powdered sugar and vanilla until soft peaks form.
11 - Spread or pipe whipped cream over pie. Garnish with chocolate shavings if desired. Slice and serve chilled.