To begin, preheat your oven to 350. Spray two pans with non-stick spray.
To a large mixing bowl, add your butter and brown sugar and beat them together with a mixture till creamed. Add your vanilla and egg and briefly blend them in.
To the same bowl, add your gluten-free flour, baking soda, salt and cinnamon and stir them together till you have a smooth, consistent cookie dough batter.
Cut or crumble your graham crackers, and measure out 1/2 cup of them. Add them and 1/4 cup of the chopped up Hershey's chocolate bars to your cookie dough and fold them into your batter.
Using a small cookie scoop, scoop overflowing cookie dough balls and space them evenly apart on your pans, with no more than 12 cookies per pan. Bake in the oven for 8 minutes.
Remove from the oven, and gently press 3-4 marshmallows into the cookies. Aim towards the middle of the cookies. Bake for another 4-5 minutes, or till the edges are set but the center is a touch undone.
While the cookies are still hot, add one Hershey rectangle into the center of each cookie. Gently press into the dough. Let the cookies cool, or enjoy a cookie warm while the chocolate in the center is still melty.
Devour!
Stored in an airtight container, these cookies are good for about a week.