Preheat your oven to 350°F and line a large baking sheet with parchment paper.

In a large mixing bowl, whisk together the granulated sugar, brown sugar, and melted butter until smooth. Add the egg and continue mixing until fully incorporated.

Add the flour, salt, and baking soda, stirring until a soft cookie dough forms. Fold in the milk chocolate chips until evenly distributed throughout the dough.

Using a standard cookie scoop (about 2 tablespoons of dough), portion the dough into 12 cookie dough balls and place them on the prepared baking sheet, leaving about 2 inches between each cookie.

Bake for 7 minutes.

Carefully remove the baking sheet from the oven and gently press one marshmallow into the center of each cookie.

Return the cookies to the oven and bake for an additional 4 minutes, or until the marshmallows have softened and the cookies are lightly golden around the edges.

Remove the cookies from the oven. While the marshmallows are still warm, gently press two candy eyes onto each marshmallow to create adorable little ghosts.

Allow the cookies to cool on the baking sheet for about 10 minutes before transferring them to a wire rack to cool completely.

Serve and enjoy!