Preheat the oven to 350F.
Beat the egg yolks,vanilla extract, sugar until they turns smooth and plate,add the flour,butter to them, mix everything well and keep aside.
Now whisk the egg whites with a pinch of salt until soft peeks forms.
Fold the whipped egg whites to the already prepared batter, mix gently until they get well mixed.
Remove quarter cup of the batter, add the green food colour and transfer the batter to a piping bag.
Line a baking sheet over a swiss roll pan or a baking tray.Pipe the batter slowly over the christmas tree pattern or any pattern as you desire.
Bake it for 2minutes in the preheated oven.Spread the remaining vanilla flavoured batter to the already baked pattern.
Bake for 10-12minutes,until the top turns firm.
Remove the baking sheet carefully, transfer it to a damp towel, roll it to see the pattern clearly on the top.
Keep aside, let it cool completely. Meanwhile, mix the mascarpone cheese and melted chocolate together until the mixture turns creamy.
Spread this chocolate mascarpone cream over the baked cake and roll again tightly.
Arrange in fridge for few hours.
Slice it and enjoy
