In a mixing bowl, whisk together the flour, baking powder, baking soda, cornstarch and salt, then put aside.

Using a electric mixer, cream together butter and both sugar for 3-4 minutes. Add the egg and finish with the vanilla.

Add the flour mixture and mix until just combined.

Tear the small marshmallows in half and roughly cut the Graham crackers and Hershey’s bar. Set aside a handful of torn marshmallows and chopped chocolate.

Add the remaining marshmallows, chopped chocolate and Graham crackers and mix until all is mixed through.

Transfer the dough to a bowl, cover and let it chill for at least a couple of hours.

Roll the dough into balls. They should each be roughly the size of a gold ball.

Pre-heat over to 350° and bake for 10 minutes on a baking sheet.

Add a few of the chocolate pieces and mini marshmallows set aside and cook for an additional 2 minutes before leaving on the tray to cool for a few minutes.