Preheat your oven to 350°F (175°C) and prepare a 9x9-inch baking pan by greasing it with butter or lining it with parchment paper.

In a large mixing bowl, whisk together the unsweetened cocoa powder, granulated sugar, all-purpose flour, and a pinch of salt until fully combined.

Melt the unsalted butter in a separate bowl and let it cool slightly. Add the eggs and whisk until smooth.

Pour the wet mixture into the dry ingredients and stir until combined, being careful not to overmix.

Spread the brownie batter evenly in the prepared pan and bake for 25-30 minutes. Use a toothpick to check for doneness.

Allow brownies to cool in the pan for 10-15 minutes, then transfer to a wire rack to cool completely before decorating.

Cut brownies into squares and use white icing to create mummy wrappings.