just saw this.
Going to make it tonight or another day this week

5 tablespoons unsalted butter, melted
1 1/2 cups cinnamon graham cracker crumbs (from about twelve 5- by 2 1/2-inch crackers)
2 tablespoons sugar
3/4 teaspoon salt
For filling
6 oz fine-quality bittersweet chocolate (no more than 60% cacao if marked)
2 tablespoons cornstarch
1/3 cup packed light brown sugar, divided
2 whole large eggs
2 large egg yolks
2 cups whole milk
1/2 cup heavy cream
1/8 teaspoon salt
1/2 stick unsalted butter, cut into tablespoons
1 teaspoon pure vanilla extract
For whipped cream
1 1/2 cups chilled heavy cream
5 tablespoons confectioners sugar
1/2 teaspoon cinnamon
For chocolate curls
1 (3- to 4-inch-thick) chunk bittersweet chocolate
Make crust:
Preheat oven to 350°F with rack in middle.
Stir together all crust ingredients. Press over bottom and up side of a 9-inch pie plate. Bake until set, 12 to 15 minutes, then cool.
Make filling:
Melt chocolate in a large bowl (see Tips).
Stir together cornstarch and 2 Tbsp brown sugar in a small bowl.
Whisk together whole eggs and yolks in another bowl, then whisk in cornstarch mixture.
Stir together milk, cream, salt, and remaining brown sugar in a heavy medium saucepan and bring just to a boil over medium heat. Pour half of milk mixture into egg mixture in a slow stream, whisking, then pour egg mixture into remaining milk mixture. Bring to a boil over medium-low heat, whisking constantly, then boil, whisking, 1 minute. Remove from heat and whisk in butter and vanilla. Strain through a fine-mesh sieve into melted chocolate and whisk to combine.
Transfer hot filling to crust and chill, its surface covered with parchment, until filling is cold, about 3 hours.
Make whipped cream:
Beat cream with confectioners sugar and cinnamon using an electric mixer until it holds stiff peaks. Spoon over chilled filling.
Make chocolate curls:
Hold chocolate in your hands (or microwave on low power in 10-second intervals) until surface softens slightly. Using a vegetable peeler (preferably Y-shaped), “peel” large chocolate curls onto a paper towel. If curls are too brittle or don’t form easily, rewarm chocolate just until surface softens.
Sprinkle curls on pie.