Preheat oven to 375 degrees F.
Whisk together flour, baking soda, salt and cinnamon in a medium bowl. Set aside.
In a large bowl, cream together butter and sugars with an electric mixer until fluffy, about 2-3 minutes.
Incorporate vanilla then add eggs one at a time, beating well after each addition.
Gradually beat in flour mixture. Fold in dark chocolate chunks and 1 cup of marshmallows
Cool bars in pan. Cut through the cookie layer into squares, making sure to cut where the graham crackers meet. Store at room temperature in an air-tight container.