Step 1

Preheat the oven to 160°C / 140° fan forced and line a 20cm square baking tin with baking paper.

Step 2

Place the butter, sugar and cocoa powder into the Thermomix bowl and heat for 3 mins/50/speed 2.5.

Step 3

Set the Thermomix to 1 min/speed 3 and add the eggs one at a time through the hole in the lid followed by the vanilla extract. Keep the Thermomix running until the end of the minute.

Step 4

Add the flour and mix for 3 sec/speed Scrape down the bowl then mix again for 3 sec/speed 5 until fully combined.

Step 5

Pour the batter into the prepared tin and bake in the oven for 30-35 minutes until the centre is just set.

Step 6

Leave to cool completely in the tin before cutting up into 16 squares.