01 - Mix graham cracker or chocolate cookie crumbs with sugar in a medium bowl. Stir in melted butter until evenly moistened. Press firmly into the bottom and up the sides of a 9-inch pie dish. Freeze for 15 minutes.
02 - Preheat oven to 350°F. Bake crust for 10 minutes, then allow to cool completely.
03 - Melt chocolate in a heatproof bowl set over a saucepan of barely simmering water, stirring until smooth. Remove from heat and cool to room temperature.
04 - Beat butter and powdered sugar with an electric mixer on medium speed until light and fluffy, approximately 2-3 minutes.
05 - Add cooled melted chocolate and vanilla extract to the butter mixture. Beat until thoroughly incorporated.
06 - Add eggs one at a time, beating on medium-high speed for 3-5 minutes after each addition until mixture achieves a silky, light consistency. This step is critical for proper texture.
07 - Spread chocolate filling evenly into cooled crust and smooth the surface. Refrigerate for at least 4 hours or until completely set.
08 - Whip cold heavy cream with powdered sugar and vanilla extract until soft peaks form. Spread or pipe over chilled pie before serving.
09 - Garnish with chocolate shavings if desired. Slice and serve chilled.