Prepare the Dough:
Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper or a silicone baking mat.
In a large bowl, cream together the softened butter, brown sugar, and granulated sugar until light and fluffy.
Beat in the eggs one at a time, followed by the vanilla extract.
In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add the dry ingredients to the wet mixture, mixing until just combined.
Gently fold in the chocolate chips, mini marshmallows, and graham cracker pieces.
Shape and Bake:
Scoop tablespoon-sized portions of dough and place them on the prepared baking sheet, spacing them about 2 inches apart.
Optionally press a few extra chocolate chunks, marshmallows, or graham cracker pieces on top of each cookie for a more decorative look.
Bake for 8–10 minutes, or until the edges are golden brown and the centers look slightly underbaked.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.