5 large egg yolks
6 Tbsp. sugar
3 Tbsp. cornstarch
1/4 tsp. salt
2 C whole milk
1 tsp. pure vanilla
7 oz. bittersweet chocolate, melted
2 1/2 Tbsp. unsalted butter, room temperature, cut into cubes
1 graham cracker crust, prebaked
For the marshmallow topping
6 large egg whites
1/2 tsp. cream of tartar
1 1/2 C sugar
1 tsp. pure vanilla
To make the filling;
1. Whisk egg yolks, sugar, cornstarch, and salt together in a heatproof bowl until thick and pale in color. Set aside
2. In a medium saucepan, bring the milk to a gentle boil. Whisk about half of the hot milk into the egg yolks to temper them, so they won’t curdle, then continuing to whisk, add the rest of the milk in a steady stream.
3. Set the bowl over a medium saucepan of simmering water (do not let the bottom the bowl touch the water) and cook the egg-milk mixture, whisking constantly, until thick and glossy, 5 to 7 minutes.
4. Remov0e the bowl from the heat and whisk in the vanilla and melted chocolate until well blended. Let the filling mixture sit for 2 minutes to cool slightly, then whisk in the butter until the custard is smooth and silky. Place a piece of plastic wrap directly on top of the chocolate filling so that a skin does not form and let cool for 30 minutes, or until it reaches room temperature.
5. When the filling has cooled, pour it into the prepared crust. Cover the pie with plastic wrap and place in the refrigerator to chill for at least 3 hours, or overnight.
To make the marshmallow topping;
6. Put the egg whites, cream of tartar, and sugar in a large heatproof bowl, set the bowl over a medium saucepan of simmering water (do not let the bottom of bowl touch the water), and whisk constantly until the sugar is completely dissolved and the egg whites are warm to the touch, 3-4 minutes. The mixture will appear pale and opaque. Rub a little of the mixture between your fingers to make sure the sugar is completely dissolved.
7. With a mixer, starting on low speed, add vanilla and whip the egg whites, gradually increasing the speed to high, until the marshmallow topping is glossy and forms stiff peaks. 5 – 7 minutes.
8. Fill a pastry bag with a large plain tip with the marshmallow topping and pipe it over the entire surface of the pie make sure it touches the crust all around, then loosely pile the rest of the marshmallow topping on top and use a spatula to spread in big swirls. Toast the topping lightly with a kitchen blowtorch, if desired.