Step 1

Preheat oven to 180ºC. Line a 20 x 30cm (base measurement) slab pan with non-stick baking paper.

Step 2

Melt the butter in a saucepan over medium heat. Remove from heat. Stir in the sugar. Add the eggs, 1 at a time, and stir until mixture is thick and glossy.

Step 3

Sift the flour and cocoa powder over the egg mixture and stir until well combined. Stir in the vanilla. Spread over the base of the prepared pan.

Step 4

Bake for 30 minutes or until a skewer inserted into the centre comes out clean. Set aside in the pan to cool completely. Cut into pieces and dust with cocoa powder.