Preheat oven to 375°F. Line a baking sheet with parchment paper.
In a saucepan over medium heat, melt the butter. Remove from heat and let cool slightly.
In a large mixing bowl, mix together the melted butter, brown sugar, and granulated sugar until smooth and fluffy.
Add the eggs, baking soda, then gradually mix in the flour until a soft cookie dough forms.
Fold in the semi-sweet chocolate chips.
On the prepared baking sheet, place one graham cracker piece for each cookie. Top each with a piece of Hershey’s chocolate and one marshmallow.
Scoop large cookie dough balls (about 2½–3 tablespoons) and place them on top of the marshmallow, making sure it’s fully covered.
Bake for 10–12 minutes, or until the edges are lightly golden and the centers are soft.
Remove from the oven, add more chocolate on top if desired, and let cookies rest on the pan for 5 minutes before transferring to a cooling rack.