In a bowl, take milk. Add vinegar and vanilla essence. Mix well and keep aside.

In another bowl, take oil and condensed milk. Whisk well and add powdered sugar and again whisk well.

Mix together dry ingredients that is maida, baking powder, baking soda and cocoa powder.

Add half of milk vinegar mixture to condensed milk mixture. Mix well and then add dry ingredients mixture. Mix all well to make smooth batter. Then add remaining milk vinegar mixture and give it a good mix to get flowing consistency smooth batter.

Transfer batter to the big baking tray. I have taken 10"by 12" tray. Spread batter evenly and tap well to remove air bubbles.

Bake in preheated oven for 10 mins.
Remove tray from the oven. After 5 mins sprinkle powder sugar on cake. Take butter paper and flip cake on it and remove the tray.

Mix little water in Nutella. Apply Nutella on all over the cake. Roll cake gently. Lastly roll butter paper over cake roll and keep roll in the freezer for an hour. After an hour, remove butter paper and cut the roll in slices.