Ingredients（成分/原料）

　　Crust
　　9 whole chocolate graham crackers
　　1 tablespoon sugar
　　Pinch of salt
　　6 tablespoons unsalted butter, melted

　　Filling
　　1 1/4 cups sugar
　　1/2 cup unsweetened cocoa powder
　　1/4 cup cornstarch
　　3 1/2 cups half and half
　　4 large egg yolks
　　3 1/2 ounces bittersweet (not unsweetened) or semisweet chocolate, chopped
　　3 ounces unsweetened chocolate, chopped
　　2 tablespoons unsalted butter
　　1 teaspoon vanilla extract Topping
　　1 cup chilled whipping cream
　　2 tablespoons powdered sugar
　　1 1/2 teaspoons instant espresso powder
　　1/2 teaspoon vanilla extract Chocolate-covered espresso beans

　　Preparation（准备）

　　For crust:
　　Preheat oven to 350°F. Finely grind graham crackers, sugar, and salt in processor. Add butter and blend to moisten crumbs. Firmly press mixture into 9-inch-diameter glass pie dish. Bake until crust sets, about 8 minutes. Cool.

　　For filling:
　　Whisk sugar, cocoa, and cornstarch in heavy medium saucepan. Gradually whisk in 1 cup half and half. Whisk in remaining 2 1/2 cups half and half and yolks. Whisk over medium-high heat until mixture thickens and boils, whisking constantly, about 12 minutes. Remove from heat. Add both chocolates and butter; whisk until melted and smooth. Mix in vanilla. Transfer filling to crust. Press plastic wrap directly onto surface of filling and chill until filling sets, at least 6 hours. (Can be made 2 days ahead. Keep chilled.)

　　For topping:
　　Beat all ingredients in large bowl until peaks form. (Can be made 1 day ahead. Cover and refrigerate. Rewhisk to thicken before serving, if necessary.) Peel plastic off pie. Cut pie into wedges. Spoon dollop of cream atop each slice. Garnish with chocolate-covered espresso beans and serve.

　　Market tip:
　　Chocolate-covered espresso beans are sold at specialty foods stores, cookware stores, and coffee bars.