Place sugar in a food processor and blend for two minutes, until sugar becomes very fine.
In a medium bowl, combine cake flour, salt, and half of the fine sugar. Sift together and set aside.
Preheat oven to 350ºF.
Combine egg whites, water, vanilla and cream of tartar in the bowl of your stand mixer. Whisk ingredients together for 2 minutes until well combined. Gradually add remaining half of sugar and Beat egg white mixture until medium peaks are formed.
Sprinkle some of the flour mixture over the top of egg white mixture. Gently fold in. Repeat until all of the flour mixture has been folded in evenly.
Spoon mixture into an ungreased tube pan and bake for 35-40 minutes, until golden brown in color and cake is cooked through.
Invert cake pan and cool upside down (cake remaining in the pan) until completely cooled.
Once cooled, run a knife along the inside tube and the outside to loosen the cake. Lift the tube from the rest of the pan and invert the cake onto a cooling rack, using the knife to loosen it from the bottom, if necessary.
To make the ganache
Finely chop chocolate and place in a bowl. Bring cream just barely to a simmer and pour over chopped chocolate. Cover with plastic wrap and let stand 2 mins. Stir with a spatula until combined and smooth.
Allow the ganache to cool a bit before using.
Place the cooling rack with cake on top over the top of your sink. Pour the ganache over the cake, spreading evenly over the sides, top, and inside.
Take the graham cracker crumbs and throw them along the bottom half of the cake. This is the best way I can describe this.
Spread or pipe marshmallow creme over the top of the cake. Carefully toast the top with a culinary torch.