FOR THE GRAHAM CRACKER LAYER:
4½ whole graham crackers (5 x 2½ inch rectangles), coarsely crumbled
2 tbsp. unsalted butter, melted
FOR THE CHOCOLATE PUDDING:
2 tbsp. unsweetened cocoa powder
1 tsp. espresso powder (optional)
8 oz. bittersweet chocolate, finely chopped
1 tbsp. whiskey (optional)
FOR THE MARSHMALLOW TOPPING:
Preheat the oven to 300? F.
Line a baking sheet with a silicone baking mat or parchment paper.
To make the graham cracker layer, combine the crumbled graham crackers, butter, sugar and cinnamon in a small bowl. Toss with a fork to blend.
Spread the mixture in an even layer on the prepared baking sheet. Bake until crisp, stirring once during baking, about 10 minutes.
To make the pudding, combine the sugar, cornstarch, cocoa powder, espresso powder and salt in a medium saucepan.
Add the egg yolks and whisk to blend. Gradually whisk in the milk and the cream.
Cook over medium heat, whisking constantly, until the mixture comes to a boil. Allow to boil for 30 seconds.
Remove from the heat and stir in the chocolate, whiskey, butter and vanilla; whisk until the chocolate and butter are completely melted and the mixture is smooth
Let the pudding cool slightly, stirring occasionally, about 10 minutes.
Spoon 1/3 cup of the pudding into each of 6 serving dishes.
Sprinkle each with some of the graham cracker mixture, dividing evenly between the dishes.
Top each with 1/3 cup more of the pudding mixture. Cover each with plastic wrap directly on the surface of the pudding. Chill for at least two hours.
to make the marshmallow mixture, combine all ingredients in the bowl of an electric mixer.
Set the bowl over a pan of simmering water and heat, whisking frequently, until an instant-read thermometer registers 160? F.
Return the bowl to the mixer fitting with the whisk attachment and whip on high speed until the marshmallow mixture forms stiff peaks.
Spoon or pipe the marshmallow mixture over the top of the chilled puddings.
Use a kitchen torch to lightly brown the marshmallow topping.
Garnish with additional crumbled graham crackers, if desired.