• Pour the milk into a mixing bowl, add the pudding mix and whisk or beat for two minutes.
• Beat 1 cup heavy cream until it starts to thicken. Add the marshmallow fluff and beat until it forms soft peaks.
• Line a 9 by 5 inch loaf pan with plastic wrap, making sure to let plenty of the wrap hang over the sides of the pan. Place one layer of graham crackers in the bottom. You may have to break some pieces to fit (save a handful of broken bits to decorate the top of the cake later).
• Put ½ cup of mini marshmallows on top in a single layer. Top with half of the marshmallow fluff whipped cream, pressing down a little so it gets in between the marshmallows. Top with half the pudding, spread into and even layer. Place another layer of graham crackers, another half cup of marshmallows, the rest of the whipped cream, and the rest of the pudding. Top it off with another layer of graham crackers. Pull the plastic wrap up and cover. Refrigerate for at least 8 hours or up to 2 days.

Before serving:

• Place the top oven rack about 4 inches from the broiler. Preheat the broiler to high. Line a rimmed baking sheet with parchment paper. Place the remaining ½ cup of mini marshmallows on the pan in a single layer. Place under the broiler, with the door ajar so you can watch closely, for 30 – 45 seconds or until they puff up and brown. Remove from the oven and let cool.
• Whip the remaining 1 cup of heavy cream with the powdered sugar and vanilla until stiff peaks form.
• Remove the cake from the refrigerator, pull off the plastic from the top, place a rectangular plate on top, and invert the plate and pan so the cake goes onto the plate. Remove the plastic wrap.
• Frost the cake with the whipped cream. Top the cake with the toasted marshmallows, reserved cracker crumbs, and shaved chocolate. Can be served immediately or refrigerated until ready to serve.