Preheat your oven to 175°C (350°F) and line your baking pan with parchment paper, ensuring it's ready for the batter.
In a heatproof bowl, melt the dark chocolate and butter together over simmering water or in short bursts in the microwave, stirring until smooth and glossy—your kitchen will fill with a rich cocoa aroma.
Stir in the sugar, then add eggs one at a time, mixing well after each addition until the mixture is shiny and smooth—watch for a glossy texture.
Gently fold in the flour just until combined, maintaining a thick, shiny batter that resembles melted chocolate pudding.
Pour the batter into your prepared pan and spread evenly with a spatula. Bake for 20–25 minutes until the edges look set but the center is slightly jiggly—your kitchen will smell irresistibly chocolaty.
Remove from the oven and let it cool in the pan for about 10 minutes, then transfer to a wire rack to cool completely—this helps the brownies set properly.
While the brownies cool, whip the heavy cream with vanilla using a mixer until stiff peaks form—that’s your whipped cream for the ghosts.
Fill a piping bag or a small zip-top bag with the whipped cream and pipe ghost shapes—heads, arms, and bodies—on top of the cooled brownies for a spooky effect.
Use mini chocolate chips to create tiny eyes and mouths on each ghost for expressive faces—press them gently into the whipped cream.
Chill the decorated brownies for about 15 minutes to help the whipped cream ghosts set and hold their shape.
Serve these playful, fudgy brownies with your favorite fall drinks and enjoy the delightful combination of rich chocolate and spooky fun!