In a large mixing bowl, cream together the butter and sugar with an electric mixer. Beat in the vanilla and egg until well combined.
In a medium bowl, combine the graham cracker crumbs, flour, baking soda, and salt. Add to the butter mixture and mix until just combined.
Press half of the dough into a parchment lined 8x8 baking dish.
Spread dough with Fluff and Nutella.
Press small pieces of the remaining dough on top of the Fluff and Nutella to form the top crust.
Bake for 20-25 minutes or until golden brown.
Cool completely before cutting.
Video
Notes
Buy a box of graham cracker crumbs or make your own by blitzing around 15 crackers in a food processor or blender.You can use a layer of Hershey's bars in place of the Nutella, if preferred.