Preheat your oven to 180°C (350°F) and grease your 9x13 inch baking pan.
Melt the butter with the chocolate chips in a microwave or double boiler until smooth and glossy, filling your kitchen with a rich chocolate aroma.
In a large bowl, mix the brownie batter ingredients according to the box instructions, then fold in the melted chocolate mixture until well combined.
Pour the batter into the prepared pan, spreading evenly with a spatula. Bake for 20-25 minutes until a toothpick inserted in the center comes out with moist crumbs.
Remove the brownies from the oven and let them cool completely on a cooling rack, about 30 minutes, until firm and set.
Once cooled, cut the brownies into small, bite-sized squares to make tiny mummies.
Prepare the icing by mixing powdered sugar, egg whites or meringue powder, and vanilla extract until stiff and smooth. The icing should be thick enough to pipe.
Fill piping bags or plastic sandwich bags with the icing, then pipe thin, uneven lines over each brownie to resemble wrappings. Let the icing set for about 15 minutes.
Gently press two candy googly eyes onto each mummy brownie, pressing slightly so they stick to the icing.
Decorate with tiny sprinkles or skulls if desired, adding extra creepiness and crunch.
Allow the decorated mummies to rest for 10-15 minutes so the icing can fully set and crack slightly, enhancing the mummy effect.
Serve these spooky brownies on a platter, ready to impress with their adorable creepiness and delicious fudgy texture.
