Preheat the oven to 180°C (350°F) and line a 9'x9' baking tin with baking paper.
Melt the butter and dark chocolate together.
Mix the eggs, sugar, brown sugar and vanilla extract together until the mixture becomes a light golden colour.
Mix in the chocolate mixture.
Stir in the flour and cocoa until just combined.
Spread the mixture into the prepared pan in an even layer.
Bake for 20-25 minutes. The top and sides will be set and the middle will have crumbs attached to a skewer inserted but should not be wet.
Allow to cool completely and slice into pieces.
Melt the white chocolate and drizzle haphazardly over the slices of brownie to create a 'mummified' effect. While the chocolate is still melted, stick two eyes on each brownie piece and allow to the chocolate to set.