Preheat your oven to 160 degrees and line the base and sides of a 20cm square baking tin with baking paper.
Place the sugar, butter cacao and cocoa into your Thermomix bowl and melt for 3 minutes, 65 degrees, speed 2 or until meted.
Add the eggs and vanilla extract and mix for 10 seconds on speed 4.
Scrape down the sides of your Thermomix bowl and add the flour and mix for 5 seconds on speed 4 before scraping down the sides and mixing for another 10 seconds on speed 4.
Pour the brownie mixture into the prepared tin and gently smooth the surface.
Place the brownies into the oven to bake for 35 minutes.
Carefully remove the cooked brownies from the oven and allow them to cool in the tin before removing, cut into small pieces .