Place the cold water into a small dish and sprinkle the powdered gelatin on top. Gently mix and then set aside for 5-10 minutes while heating the maple syrup.
Put some water into a medium sized sauce pot and place on the stove. Place the ⅓ cup maple syrup into the bowl of a stand mixer and place the bowl on top of the medium sized sauce pot creating a double boiler. Gently heat the maple syrup. You want the maple syrup to be hot to the touch but not boiling. Once the maple syrup is hot, scoop out the gelatin and place into the syrup and allow to melt
Once the gelatin is melted, transfer the bowl to the stand mixer with the whisk attachment and whip on high. The marshmallows take about 5-6 minutes to form. You should see the maple syrup start turning white as more and more air in incorporated into the mixture. The marshmallow is done once the mixture is white, fluffy and has a medium firmness to it.
Working quickly, scrap out the fluff and spread out on top of the chocolate layer. The marshmallow contains gelatin so it will start to cool and set up fairly quickly. Once it is spread out into an even layer, place under the broiler and broil until lightly golden brown or use a kitchen blow torch and toast.
Once the marshmallow is toasted, sprinkle with the extra graham cracker topping. Take the reserved chocolate ganache, add a touch more maple syrup until the chocolate has thinned out a bit and then drizzle on top of the bars.
When ready to eat, gently warm a knife under hot water then wipe away any excess water and gently cut into 12 bars. Enjoy!