We love the cinnamon in Mexican chocolate. For this pie, we surround a smooth chocolate-pudding filling with cinnamon—a crumbly spiced graham cracker crust below and cinnamon whipped cream on top.
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.
Cooks’ notes:
Crust can be baked 2 days ahead and kept, loosely covered with foil (once cool), at room temperature.
Pie can be chilled, loosely covered with plastic wrap (once cold), up to 1 day.