Preparation

做布丁

• 将巧克力融化成20秒钟的中型微波炉中的中型微波安全碗，每次爆发后搅拌，或将巧克力放在中等大小的碗中，将融化了。搁置。
• 同时，将牛奶，奶油和糖搅拌在一个大锅中。在玉米淀粉，盐和可可粉中搅拌。最后，在轻轻打的鸡蛋和蛋黄中搅拌。将锅放在中火上，不断搅拌，煮至10至15分钟的气泡开始在表面上溅出。让布丁煮沸，嘲笑1分钟，然后从火上移开。
• 将布丁通过细网滤器过滤到一个大碗中。搅拌融化的巧克力，香草和黄油。用保鲜膜覆盖布丁的表面，以防止皮肤形成，然后将碗放入冰箱中，直到布丁完全冷却。这将需要几个小时，最好在一夜之间完成。为了加快过程的速度，将布丁放在浅容器中，而不是深碗。

组装蛋糕

• Remove the pudding from the refrigerator, and whisk to loosen. Place about one-third of the pudding on the bottom of a 9×13-inch pan and spread with an offset spatula or butter knife into an even layer. Add a layer of graham crackers, about one sleeve (or 9 crackers), breaking them up to create a solid layer of crackers. Continue layering the pudding and crackers twice more, until you have three layers of each. Place the pan in the refrigerator while you make the topping.

做浇头

• Place a large bowl over a pot of simmering water. Do not allow the bottom of the bowl to touch the water. Add the egg whites, sugar, water, corn syrup, cream of tartar, and salt. Using a hand-held electric mixer, beat the egg white mixture on high speed until stiff and glossy, about 7 minutes. Remove the bowl from the saucepan of hot water, add the vanilla, and continue beating, 2 minutes. (Alternatively, whisk the egg mixture in the bowl of a stand mixer over the simmering water until it is warm to the touch, and then transfer the bowl to a stand mixer and proceed as above.)
• Remove the cake from the refrigerator and spread the warm topping over the top. Work quickly, as the topping begins to set as it cools. Toast the marshmallow with a mini kitchen torch, if you have one, or place the cake in the oven under the broiler briefly, watching it closely so that it doesn’t burn. Once cool, cover with plastic wrap and refrigerate, for 6 to 8 hours, preferably overnight.
• To serve, use a spatula or large serving spoon to portion out pieces.