Preheat oven to 350 F. Line a baking sheet with parchment paper.
Microwave the butter and chocolate until melted. Set aside.
In a bowl, whisk sugars and eggs.
Add vanilla.
Pour in the melted chocolate and combine.
Add dry ingredients until combined.
Lay graham cracker squares on the parchment paper and top with marshmallows.
Use an ice cream scoop to put batter on top of marshmallow carefully.
Bake 12-13 mins and cool.