Preheat your oven to 350°F (175°C) and grease your baking pan to ensure easy removal of the brownies.
In a large mixing bowl, combine the brownie mix with eggs and vegetable oil, stirring until the batter is smooth and glossy, about 2 minutes.
Pour the batter into the prepared baking pan, spreading it evenly with a spatula to create a flat, smooth surface.
Bake for about 25 minutes, or until the edges are set and a toothpick inserted into the center comes out with moist crumbs.
Remove the brownies from the oven and allow them to cool slightly, just enough to handle comfortably but still warm for the marshmallows.
Using a sharp knife, carefully cut large marshmallows in half to create flat, ghost-shaped faces, or leave whole if desired.
Arrange the marshmallow ghosts onto the slightly warm brownies, pressing gently to encourage them to melt slightly and adhere, creating a soft, melting look.
Place the baking pan under the broiler for a few seconds, watching carefully, until the marshmallows are just toasted and have melted into cute ghost faces with slight golden tips.
Meanwhile, melt the chocolate chips in a microwave-safe bowl in 30-second bursts, stirring between each, until smooth and glossy.
Using a spoon or piping bag, drizzle the melted chocolate over the marshmallow ghosts for a shiny finishing touch that adds depth and a haunted look.
Let the brownies cool completely before slicing into squares — this allows the marshmallows to set and prevents the ghosts from shifting.
Enjoy these spooky, chocolatey brownies with playful marshmallow ghosts, perfect for Halloween parties or a fun fall treat.
