Preheat oven to 350℉
Line a 9x13 baking pan with parchment paper, or use butter or cooking spray to grease pan
Melt the butter in a large mixing bowl in the microwave
Add brown sugar and white sugar, and mix until fully combined
Mix in the ground cinnamon and vanilla extract
Add the eggs, and beat until fully combined
Gradually add the flour, one cup at a time, and mix well. Mix in the baking powder and sea salt
Fold in the chocolate chips, and transfer cookie dough mixture into prepared baking pan
Bake for 20 minutes, or until cookie bars are a light golden brown, and a toothpick inserted in the center comes out fairly clean
Remove from oven, evenly place the halved marshmallows over baked cookie bars, and return to oven and broil for 2 minutes or until marshmallows are golden brown
Remove from over, allow to cool slightly, and top with chocolate bar bits and graham cracker pieces
Allow to cool completely before serving