Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a medium bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, and nutmeg.
In a large bowl, cream the softened butter, granulated sugar, and brown sugar until light and fluffy.
Add the egg and vanilla extract, mixing until well combined.
Stir in the pumpkin puree until smooth.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the chocolate chips, mini marshmallows, and graham cracker crumbs.
Drop rounded tablespoons of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake for 10-12 minutes, or until the edges are golden.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.