In a mixing bowl add condensed milk ,oil, vanilla essence mix well
Then sieve maida, baking powder, baking soda, mix well
Add 2-2 tablespoon milk as required and make semi liquid batter
Now make 2 equal parts from batter
Add cocoa powder in one part well
Now pore both batter in separate piping bag
In baking trey arrange butterpaper now make one line of batter with cocoa better and second line with white batter repeat this process till end
Now in preheat oven bake it for 15 min. On 180 degree,then demould it after cool it on eluminium foil
Then apply whipped cream on it then role it and cool it in fridge for 1/2 hours
Then cut it in 1 inch and sprinkle chocolate ganache and dried rose petals.