Preheat oven to 375°F. Generously butter a 9-inch deep pie dish.
Combine cookies and powdered sugar in the bowl of a food processor and pulse until finely ground. Add melted butter and pulse until crumbs are evenly moistened. Transfer crumbs to prepared pie dish and press into the bottom and up the sides. Bake for 12-15 minutes, or until fragrant and set. Let cool completely.
When the crust has cooled, make the filling. Combine sugar and eggs in a small saucepan over medium-low heat. Cook, whisking constantly, until sugar is dissolved and the temperature reaches 160°F. Remove from heat and stir in chocolate and vanilla. Let cool, stirring occasionally, until completely cool to the touch.
Use a handheld mixer to cream the butter until smooth and lightened. Slowly add the cooled chocolate mixture and beat until combined and fluffy, 3-5 minutes.
Clean the beaters and add cream to a separate bowl. Beat the cream on medium speed until it thickens, then add the powdered sugar. Continue to whip until soft peaks form. Fold the whipped cream into the chocolate in three additions. Transfer to cooled crust and smooth top. Chill for at least 4 hours or overnight.
When ready to serve, make the whipped cream. Beat cream on medium speed until thickened, then add the powdered sugar. Continue to beat until soft peaks form. Spoon onto the center of the chilled pie. Garnish with chocolate shavings and curls.