Preheat oven to 180 degree C. Take a round cake pan or any of your favourite mould and oil it well. Sprinkle cocoa over and coat it on all sides. Set aside.
Take flour, cocoa, baking soda in a sifter and sieve well.
Take oil, water, sugar, coffee and vanilla in a bowl and whisk well.
Add in the flour mix and fold gently. Fold in the white chocolate and mix well.
Pour this in the prepared pan and bake for 35 to 40 mins.
Insert a tooth pick to check whether the cake is done, if the toothpick comes clean then the cake is done..
Remove it and let it cool for 15 mins. Invert it and cool completely.