• Preheat oven to 370℉/180℃. Line a 8″ square baking tin with greaseproof paper. 
• Melt the dark/semi-sweet chocolate by breaking up into small pieces in a bowl and heating for 30 second intervals in a microwave, stirring in between. Set aside to cool whilst making the brownies. Alternatively, set up a double boiler. Do this by placing a heatproof bowl over a small pot of simmering water. Add the chocolate to the heatproof bowl and stir until melted. 
• In a large bowl or the bowl of a stand mixer combine the melted butter, and both the brown and granulated sugars on a medium speed until totally combined.
• Add the eggs and vanilla and mix again. Then check that the chocolate has cooled a little before adding in and combining.
• Add in the flour and cocoa powder and fold together. Pour the batter into the prepared pan. Bake 25-28 minutes. Let cool.

For the Brigadeiro Layer

• Once the brownie has cooled, make the Brigadeiro layer.
• Add condensed milk, butter and cocoa powder to a saucepan over a low/medium heat. Stir continuously for about 10 minutes, until thickened. Pour this over the brownie.
• Top with a generous amount of chocolate sprinkles and let set 1 hour before slicing. (Speed this up by refrigerating 30 minutes, or overnight).