In a saucepan, heat the heavy cream until bubbles start to form on the side, about 2 minutes.
Add the chopped chocolate to a medium sized bowl and pour the hot heavy cream on top. Let it sit for a minute and then whisk until smooth. Reserve.
Process the graham crackers until finely crumbed. Add the melted butter and pulse a few times until the mixture resembles wet sand. Reserve.
To assemble the s'mores in a jar, start by adding 1/4 of the Graham cracker mixture to the bottom of the mason jars. Then add 1/4 of the marshmallow fluff, 1/4 of the chocolate ganache and finish off my topping with mini marshmallows.
Using a cooking torch, toast the marshmallows until browned and serve!
Notes
If you don't own a torch, just line the marshmallows in a baking sheet and put them under the broiler until toasted.