• Preheat oven to 190C, line a 12"x10" swiss roll pan with parchment paper..

Make egg yolk batter

• Beat egg yolks and sugar just a little (I find that if I beat too much, the cake becomes rough).
• Add the oil, flours and vanilla essence. Mix till just combined. Do not overmix.
• Set aside.

Make egg white batter

• Beat egg white until frothy then add the cream of tartar.
• A squeeze of lemon will stabilize the meringue but optional.
• Add sugar gradually, and then continue to beat until soft to medium peaks form. If you accidentally or purposely beat it to stiff peaks, then add more oil to the egg yolk mixture.
• Divide into roughly 3 equal portions.
• Fold in each portion into the egg yolk mixture.
• Bake on medium to high rack for 9 to 12 minutes. Do not overbake. If you overbake, your cake will crack with you roll it.

Make butter cream

• Beat butter and cream until almost white.

Make the roll

• After the cake has cooled for 5 minutes, remove it from the parchment paper.
• Put it below another parchment paper sprinkled with sugar (if desired).
• Roll the cake up together with the parchment paper roughly, and then release it.
• When cake is cooled, apply the butter cream and roll up again, using the parchment to guide, but don't roll the parchment paper in this time.
• To tighten the roll, use a long ruler to tuck the sides in. (optional)