Don’t be intimidated by this long recipe. It has many steps but you’ll be rewarded with a masterpiece! To simplify the process, the pie can be made over two days: make the crust and cake on the first day, and the pudding and whipped cream on the day that you plan to serve it.
Mississippi Mud Pie
For the cookie crust:
About 1 lb. (500 g.) chocolate sandwich cookies (about 40), such as Oreos, processed to very fine crumbs (about 3 1/2 cups /10 1/2 oz./330 g.)
5 Tbs. (2 1/2 oz./75 g.) unsalted butter, melted
Flourless chocolate cake batter (recipe follows)
For the pudding:
3/4 cup (6 oz./185 g.) sugar
1/2 cup (1 1/2 oz./45 g.) natural cocoa powder
1/4 cup (1 oz./30 g.) cornstarch
1/4 tsp. kosher salt
4 large egg yolks
2 1/2 cups (20 fl. oz./625 ml.) whole milk
3 Tbs. unsalted butter
2 tsp. pure vanilla extract
3 oz. (90 g.) dark chocolate, chopped
For the topping:
1 1/4 cups (10 fl. oz./310 ml.) heavy cream
2 Tbs. sugar
To make the crust, preheat the oven to 300ºF (150ºC). Lightly spray the bottom and sides of a 9-inch (23-cm.) springform pan with nonstick cooking spray. Line the pan with parchment paper and lightly spray the parchment. Place the cookie crumbs in a bowl, add the melted butter, and stir until combined. Press the crumb mixture into the bottom and up the sides of the prepared pan. Chill in the freezer for about 10 minutes. Bake until the crust is dry to the touch, about 10 minutes. Let cool on a wire rack. Raise the oven temperature to 350ºF (180ºC).
Prepare the cake batter as directed, then pour the batter into the partially baked crust. Bake until the cake is set but still jiggles slightly, 38-42 minutes. Transfer to a wire rack and let cool completely. As it cools, the cake will deflate in the center and look sunken. Tightly wrap the cake and refrigerate for at lest 3 hours or up to overnight.
To make the pudding, in a saucepan, whisk together the sugar, cocoa, cornstarch and salt. Add the egg yolks and half of the milk and whisk until combined. Whisking constantly, slowly pour in the rest of the milk. Bring the mixture to a boil over medium heat, whisking constantly to keep it from scorching.
Cook for 30 seconds, then strain into a heatproof bowl. Add the butter, vanilla and chocolate and whisk until combined. Continue to whisk to cool the mixture slightly. Let the pudding stand for 15 minutes. Cover with plastic wrap pressed directly onto the surface of the pudding to prevent a skin from forming. Refrigerate until chilled, 2-3 hours.
Stir the chilled pudding to loosen it, then pour on top of the cake, making sure to stay inside the crust. Spread the pudding in an even layer. Chill for at least 30 minutes. Meanwhile, whip the cream and 2 tablespoons sugar to medium peaks. Spread the whipped cream over the pudding. Sprinkle with chocolate shavings. Remove the sides of the pan, cut the pie into wedges, and serve. The pie can be kept, covered, in the refrigerator for up to 2 days. Makes 1 large pie.
Flourless Chocolate Cake Batter
4 Tbs. (2 oz./60 g.) unsalted butter
6 oz. (185 g.) dark chocolate, chopped
2 Tbs. plus 1 tsp. instant espresso powder
1/4 cup (2 fl. oz./60 ml.) strong brewed coffee, at room temperature
1/4 tsp. kosher salt
1 Tbs. pure vanilla extract
6 large eggs, separated, at room temperature
1 cup (8 oz./250 g.) sugar
Melt the butter and the chocolate in a heatproof bowl set over (not touching) simmering water in a saucepan. Remove from the heat and whisk until smooth. Let cool. In a small bowl, whisk together the espresso powder, coffee, salt and vanilla. In the bowl of a stand mixer fitted with the whisk attachment, beat the egg yolks with 1/2 cup (4 oz./125 g.) of the sugar on medium-high speed until the mixture is light and has almost doubled in volume, about 5 minutes. Add the chocolate mixture and beat until just combined.
Reduce the speed to low, add the coffee mixture, and beat until just combined. In a clean bowl, using the whisk attachment, beat the egg whites on medium-high speed until foamy. Gradually raise the speed to high, add the remaining 1/2 cup sugar, and beat until soft peaks form. Scoop 1 cup (8 fl. oz./250 ml.) of the egg whites into the chocolate mixture and gently fold in using a rubber spatula. After about 30 seconds of folding, add the remaining egg whites and fold in until almost completely combined. Take care not to overmix. Use as directed. Makes one 9-inch (23-cm.) cake.