In a large mixing bowl (or in the bowl of your stand mixer), cream together the butter, brown sugar and granulated sugar. Mix the butter and sugars until light and fluffy.
Add the two eggs and vanilla. Stir to combine, scraping the edges of the bowl as needed.
In a small bowl, combine the flour, baking soda and salt. Add the dry ingredients to the butter mixture and mix (on low speed) until just combined. I like to add the dry ingredients in 2 parts. Mix in the chocolate chips.
Chill the finished dough in the refrigerator for at least 2 hours. I also sometimes scoop and freeze the dough for 1 hour if I am in a hurry to have cookies.
Preheat the oven to 375°. Line two half sheet pans with parchment paper. Scoop the dough (or place frozen scoops) onto the prepared pans, about 2 inches apart. Bake the cookies for 10-12 minutes, or until the edges are lightly browned but the centers are still soft. Remove the cookies from the oven and allow them to sit on the baking pans for 5-7 minutes before transferring them to a cooling rack.
To Make the S'mores Topping
Once the cookies have cooled arrange cookies on a half sheet pan.
Layer the broken graham cracker pieces, milk chocolate chips, and marshmallows on top of each cookie. I like to work in that order...graham crackers, chocolate chips, and finally the marshmallows.
Turn your oven to broil.
Place the tray of cookies into the oven and broil until the marshmallows are golden brown and the chocolate chips are slightly melted.
Allow to cool before serving. The cookies can be stored in an airtight container for 2-3 days.
Video
Notes
These are also really fun to make in a mini muffin pan. If you decide to do this, bake the cookies first, and then top with the graham cracker, a square of Hershey's Chocolate, and ½ of a regular sized marshmallow. Then broil until the marshmallow is golden brown.