Preheat oven to 160°C. Line a baking tray with baking paper.

Whisk charcoal into milk, set aside.

Whisk half of the castor sugar with egg yolks until light and airy (ribbon stage).

Lightly whisk in the oil, charcoal milk and vanilla extract.

Sift in the flours and gently fold through.

Beat egg whites, cream of tartar and remaining sugar until stiff peaks and fold into batter.

Pour onto the lined baking tray and smooth into a 1 cm thick rectangle. Bake 8 mins.

Allow to cool.

Smear with whipped cream and cut into 5 even strips. Lay strips on top of each other.

Serve with vanilla ice cream and charcoal dusted chocolate crumbs etc.