Preheat oven to 350℉. Line a 9×13 baking pan with parchment paper, or grease the pan with butter or cooking spray.

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 the cookie dough mixture into the 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 the baked cookie bars, and return to oven and broil for 2 minutes or until marshmallows are golden brown.

Remove from oven, allow to cool slightly, and top with chocolate bar bits and graham cracker pieces.

Allow to cool completely before serving.