Ingredients

Makes one 9-inch pie

　　

For the Crust

1 1/4 cups graham cracker crumbs

　　1/4 cup (1/2 stick) unsalted butter, melted

　　3 tablespoons sugar

　　Pinch of salt

　　

For the Filling

1/3 cup sugar

　　1/3 cup Dutch-process cocoa powder

　　2 tablespoons cornstarch

　　1/8 teaspoon salt

　　1 1/2 cups whole milk

　　3 ounces bittersweet chocolate, finely chopped

　　2 tablespoons unsalted butter, cut into small pieces

　　1/2 teaspoon pure vanilla extract

　　

For the Topping

1 1/2 teaspoons unflavored gelatin

　　3/4 cup sugar

　　1 tablespoon cornstarch

　　1/8 teaspoon salt

　　1 cup whole milk

　　1 teaspoon pure vanilla extract

　　2 tablespoons light rum

　　4 large egg whites, room temperature

　　

Step 1

Make the crust: Stir together the graham cracker crumbs, butter, sugar, and salt in a bowl. Press into the bottom and up the sides of a 9-inch pie plate. Refrigerate until firm, about 30 minutes. Preheat the oven to 350°F. Bake until the crust is set and begins to turn golden brown, about 12 minutes. Let cool completely on a wire rack.

　　

Step 2

Make the filling: Sift together the sugar, cocoa powder, cornstarch, and salt into a medium saucepan. Gradually whisk in the milk. Cook over medium-high heat, stirring constantly, until almost boiling. Reduce heat to medium; add the chocolate. Cook, stirring constantly, until the chocolate has melted and the mixture is thick, about 2 minutes. Remove from heat; whisk in the butter and vanilla until smooth. Spread the chocolate mixture over the crust. Refrigerate until cold and firm, about 1 hour.

　　

Step 3

Make the topping: Prepare an ice-water bath; set aside. Sprinkle the gelatin over 2 tablespoons cold water in a small bowl. Let stand until soft, about 3 minutes. Whisk 1/4 cup sugar, the cornstarch, and the salt in a medium saucepan. Gradually whisk in the milk. Cook over medium-high heat, stirring constantly, until the mixture is thick and boiling, about 5 minutes. Remove from heat; stir in the gelatin mixture, and let cool completely. Stir in the vanilla and rum. Briefly place the pan in the ice-water bath to thicken slightly, if needed. Do not let it set completely. Set aside.

　　

Step 4

In the bowl of an electric mixer fitted with the whisk attachment, beat egg whites on medium-low speed until soft peaks form. Reduce speed to low; continue beating while you make the syrup.

　　

Step 5

Bring the remaining 1/2 cup sugar and 3 tablespoons water to a boil in a saucepan, stirring to dissolve the sugar. Brush down the sides of the pan with a wet pastry brush to prevent crystals from forming. Cook, without stirring, until the syrup registers 240°F on a candy thermometer.

　　

Step 6

Raise the mixer speed to high, and beat the egg whites just until stiff peaks begin to form. Immediately pour the syrup into the egg whites in a slow, steady stream near the side of the bowl, avoiding the whisk (it might splatter). Beat until glossy and cooled, about 7 minutes.

　　

Step 7

Fold the meringue mixture into the reserved gelatin mixture in 3 batches until just combined. Mound the mixture into the chocolate-filled crust. Refrigerate the pie for 2 1/2 hours or overnight before serving.

　　Cooks' Note

　　The egg whites in this pie are not fully cooked; it should not be prepared for pregnant women, babies, young children, the elderly, or anyone whose health is compromised.

　　Reprinted with permission from The Martha Stewart Living Cookbook: The New Classics by Martha Stewart Living Magazine, copyright © 2007. Published by Clarkson Potter, a division of The Crown Publishing Group.Buy the full book from Amazon.