Preheat oven at 180 deg C. Line 10 x 11 inch baking tray with parchment paper.
In a large bowl, mix egg yolks, vanilla extract, sugar, cooking oil and fresh milk together with a hand whisk, mix well and add in sifted flour, mix well again. Divide egg yolk batter into two portions and blend the cocoa paste into one of the egg yolk batter.
Meringue - Whisk egg whites to foamy and add sugar in 3-4 batches, continue to whisk egg white to glossy and peaks form.
Gently fold half of the meringue to the egg yolk batter and cocoa batter with a rubber spatula.
Place the prepared baking tray on the table top with a sauce plate underneath at one side (so that the batter will not spread out quickly)
Gently pour in the plain batter at one side and spread out with a rubber spatula.
Then place the tray flat on the table and pour the cocoa batter at the other side. Create patterns with a pair of chopsticks.
Gently tap the tray to release air bubbles. Bake in preheated oven at 180 deg C for about 13 minutes. Remove cake from pan, remove the parchment paper and leave to cool.
Place sponge cake (can use either side) on a plastic sheet or parchment paper (with a dry cloth placing beneath the plastic sheet to prevent slip while rolling the cake).
Whisk fresh topping cream to peak form and spread on to sponge cake followed by the pitted cherries.
Gently roll up the sponge cake to make a Swiss roll and chill it for a few hours or overnight.