Melt dark chocolate in the micro wave and set aside

In another bowl, sift cake flour, cocoa powder, baking soda and baking powder

Whip egg white till frothy, add cream of tartar and add caster sugar in 3 stages until stiff peak

In another bowl, whisk egg yolks with oil, add vanilla extract and melted chocolate and stir to combine, add fresh milk and whisk in the flour mixture until well

Gently fold egg whites into the batter in 3 stages until fully combine

Pour into 20cm chiffon pan and bake at 160 c for 50 minutes then 170 c for 10 minutes,

Invert pan immediately after baking and leave to cool completely before unmoulding