Preheat oven to 350 degrees. In a food processor, pulse cookies until finely ground. Transfer to a medium bowl; set aside. To processor, add almonds and 3 tbsp sugar and pulse until almonds have the texture of coarse meal. (Be careful not to grind them into nut butter.) Add ground nuts to cookies and stir in 6 tbsp melted butter. Press into bottom and sides of a 9-inch deep-dish pie plate. (Crust should be fairly thick.) Bake on center rack 15 minutes; let cool.
Put egg yolks in a medium bowl and beat to blend; set aside. In a medium saucepan over medium-high heat, stir together milk, 3/4 cup sugar, cornstarch, and salt. Bring to a gentle simmer, stirring constantly. (Mixture will begin to thicken.) Reduce heat to medium.
Whisking constantly, pour 1/2 cup hot milk mixture into egg yolks, then pour egg-milk mixture into saucepan. Bring to a simmer (about 190 degrees on an instant-read thermometer), stirring constantly with a wooden spoon. (It will thicken noticeably.) Remove from heat and stir in chocolate, vanilla, and 2 tbsp butter.
Pour chocolate filling into a medium metal bowl, then set bowl in a larger bowl of ice and cold water and let cool 5 minutes, stirring constantly, until filling reaches room temperature. Pour filling into prepared crust and cover with plastic wrap, pressing it directly onto surface (to prevent a skin from forming). Chill until cold, at least 3 hours and up to 1 day.
Just before serving, combine cream and remaining 1 tbsp sugar in a chilled bowl. With an electric mixer on high speed, beat cream until medium peaks form. Spread whipped cream in a thick dome over chocolate filling. Grate chocolate over pie.
NOTES: "You can prepare this pie through Step 4 up to 1 day ahead; top with whipped cream just before serving.".