- 5 tablespoons unsalted butter, melted
- 1 1/2 cups cinnamon graham cracker crumbs (from about twelve 5-by 21/2-inch crackers)
- 2 tablespoons sugar
- 1/8 teaspoon salt
- 6 ounces 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
- 1 1/2 cups chilled heavy cream
- 5 tablespoons confectioners sugar
- 1/2 teaspoon cinnamon
- 1 (3-to 4-inch-thick) chunk bittersweet chocolate
- 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.
- Melt chocolate in a large bowl.
- Stir together cornstarch and 2 tablespoons 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.
- Beat cream with confectioners sugar and cinnamon using an electric mixer until it holds stiff peaks. Spoon over chilled filling.
- 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.