Preheat your oven to 350°F (175°C). Line an 8×8-inch baking pan with parchment paper or lightly grease it so the brownies release easily after baking.

In a medium mixing bowl, whisk together the melted butter and sugar until smooth and glossy. Add the eggs and vanilla extract, then whisk again until everything is fully combined and slightly thickened.

Sift in the cocoa powder, flour, and salt. Gently mix everything together using a spatula or wooden spoon until just combined. Avoid overmixing, which can make the brownies less tender.

Fold the chocolate chips into the batter so they are evenly distributed throughout the mixture.

Pour the batter into the prepared pan and spread it evenly. Bake for 20–25 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.

Allow the brownies to cool completely before decorating. Add Halloween sprinkles, candy eyes, or pipe frosting to create spider webs, monsters, or spooky faces.

Cut the brownies into squares and arrange them on a plate for a festive Halloween dessert.