3 packages of graham crackers, roughly broken up
20 tablespoons (2 ½ sticks) unsalted butter, melted
7 ounces bittersweet chocolate, finely chopped
1 cup heavy cream
1 large egg, at room temperature for 30 mins
For marshmallow topping:
3/4 cup sugar
1/4 cup light corn syrup
1/2 teaspoon vanilla
Vegetable oil, for greasing
Preheat oven to 350 degrees
Bake the pie for 20 to 25 minutes, just until the chocolate is mostly set but slightly jiggly in the center.
Cool the pie for an hour.
Make the marshmallow topping by adding ¼ cup cold water to the bowl of a heat-proof stand mixer fitted with the paddle attachment. Sprinkle the gelatin over the water and let it stand until firm, about 1 minute.
Begin beating the gelatin mixture on medium speed, then very carefully pour in the hot sugar syrup in a slow stream. Try your best to avoid the paddle and the sides of the bowl.
Once all the syrup has been added, continue beating it on medium speed until the mixture has tripled in volume and is thick and glossy, about 5 minutes.
Add the vanilla and beat it just until combined and then immediately pour the marshmallow topping over the pie. It will be loose enough to spread. Refrigerate the pie for one hour, uncovered, then cover it with plastic wrap that has been coated lightly in vegetable oil and chill it for 3 more hours.
Preheat the broiler
Place the pie on a cookie sheet, remove the plastic wrap and cover the pie edges with a pie shield or foil.