Make the Sponge Cake

1. Preheat and Prep: Preheat the oven to 150°C. Line a 9 x 13 inch (33 x 23 cm) baking pan with a non-stick baking sheet.
2. In a large bowl, whisk the oil and milk together until fully emulsified. Stir in the vanilla extract until combined,
3. Sift in the cake flour and salt.   Whisk gently until no dry streaks remain.
4. Finally, add the egg yolks and whisk until the batter is completely cohesive, silky, and glossy.

Whisk the Egg Whites

1. In a clean, dry bowl, combine the egg whites, sugar, and lemon juice. Beat on high speed until the mixture thickens and you begin to see distinct trails left by the whisk on the surface.
2. Reduce the mixer to low speed and continue beating for 10–20 seconds; this “polishes” the meringue by breaking down large, irregular bubbles into a uniform, stable foam. Stop when you reach medium peaks, where the tip gently curls over like a bird’s beak when the whisk is lifted.
3. Gently fold 1/3 of the meringue into the yolk mixture to lighten it. Then, pour the yolk mixture back into the remaining egg whites until fully combined and no white streaks remain.

Bake and Cool the Cake

1. Pour the batter into the prepared pan, move the cake pan to let the batter level it out itself, especially the four corners.  Use a cake scraper to smooth out the surface.  Bake for 25 – 30 minutes, then higher the oven temperature to 180°C to bake for further 3 minutes to dry the surface.
2. Remove from the oven, remove from the pan, and let it cool on a wire rack slightly and peel off the baking sheet around the sides.
3. When it is slightly cool, place a sheet of parchment paper on top and flip the cake over.
4. Roll the cake into a log with the help of the parchment paper.
5. Wrap the cake with a kitchen towel to keep it moist and soft.  Let it cool on the countertop.

Make the Filling and Assemble

1. Combine the icing sugar and salt together.
2. Add the chilled heavy cream, icing sugar, vanilla extract and salt in a chilled mixing bowl.  Whisk everything together at high speed until stiff  peaks form.
3. Once the cake is completely cool, fill the centre with a generous amount of whipping cream and spread the rest of the cream evenly over the cake, leaving a 1-inch border at one edge.
4. Roll the cake tightly, starting from the opposite end, using the parchment paper to assist.
5. Wrap the roll in parchment paper and refrigerate for 30 mins to set.
6. Before serving, trim the edges for a clean look.
7. Place the cake on your desired serving plate and slice.