To make the chocolate graham cracker cups. Melt the chocolate in a microwave safe bowl on 30 second intervals, stirring after each, until melted and smooth. Place 12 cupcake liners in a cupcake mold. Using the back of a spoon or a pastry brush to smooth the chocolate up the sides of the liners. Add a few pieces of crushed graham crackers to the bottom of each cup, drizzle with any reaming chocolate. Place in the freezer for 10 minutes or the fridge for 20.

Make the Mousse. In a microwave safe bowl add the chocolate, butter and 1 tablespoon water. Microwave on 30 second intervals, stirring after each, until melted and smooth. Set aside to cool.

In a small sauce pan whisk together the egg yolks, 2 tablespoons water and sugar. Place on the stove over medium heat and stir constantly until the sauce thickens slightly and just coats the back of a spoon, about 2-3 minutes. Stir the melted chocolate into egg mixture until completely smooth. Place in the fridge while you whip the cream.

Place the cream in the bowl of a stand mixer and whip cream until stiff peaks form. Make sure not to over-beat, cream will then become lumpy and butter-like.

Now add half the whipped cream with cooled chocolate mixture. Gently fold the cream into the chocolate until no more streaks remain. Add the remaining cream and gently fold into the mousse.

Remove the chocolate cups from freezer and fill to the top with the chocolate mouse. You may have left over mousse, this can be stored in the fridge for up to a week or frozen if needed. Place the cups in the fridge for at least 2 hours (or the freezer for 1).

Once your are ready to serve, make the marshmallow frosting. Bring a small pot of water to a simmer. In a heat proof bowl, add the egg whites, sugar and cream of tarter. Place the bowl over the simmering water and whisk constantly for 4 minutes or until a candy thermometer reads 160 degrees F. Remove from the heat and beat the mixture, starting on low speed and gradually increasing the speed until stiff peaks form. Stir in the vanilla.

Pipe or spoon the frosting onto the cold chocolate mouse cups. If desired garnish with crushed graham crackers and then using a kitchen torch or a long handled lighter (this is not recommended, but it did work in a pinch) toast the top of the frosting. Drizzle with chocolate ganache.

To make the chocolate ganache, add the chocolate, heavy cream and a pinch of salt to a heat proof bowl and microwave on 30 second intervals, stirring after each until melted and smooth. Whisk in vanilla. Pour the warm sauce over the toasted marshmallow frosting.