Preheat the oven to 350°F. Line a cookie sheet with parchment paper or a silicone baking mat and set aside.
In the bowl of the stand mixer or with an electric hand mixer, cream together the butter, brown sugar and granulated sugar until light in color and fluffy in texture.
Scrape the sides of the bowl and then mix in the eggs and vanilla.
Add the flour, 1 1/2 cups graham cracker crumbs (reserving the remaining crumbs for later), baking soda, baking powder and salt. Mix until a dough forms.
Portion the dough out into 3 tbsp portions. Roll into a ball and then roll into the remaining graham crackers crumbs before arranging on the prepared baking sheet.
Repeat with remaining dough.
Bake at 350°F for 11-13 minutes or until the cookies have spread and the centers no longer look glossy.
Remove from the oven and allow the cookies to cool.
Once cool, microwave the chocolate chips and sweetened condensed milk together for 30 seconds at a time until smooth. Stir between intervals.
Once smooth, spread the chocolate onto the top of each cookie.
Allow the chocolate layer to set, and once set, make the marshmallow frosting by combining the butter, powdered sugar, vanilla and marshmallow cream until smooth.
Spread the frosting onto the top of each cookie and top with some graham cracker crumbs. You can also add a square of chocolate, if desired.
Store at room temperature for up to 3 days. Enjoy!