Chocolate Cinnamon Cream Pie

Ingredients

• 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