Mix in well icing sugar and oil in a bowl.
To the same bowl add vanilla essence and buttermilk. Give a good mix. In another bowl sieve flour, cocoa powder, baking powder, baking soda and salt together.
Cut and fold dry ingredients and we'll ingredients till dropping consistency.
Bake in well greased cake tin at 180 degrees preheated oven for 30 minutes

For decoration,
I used chocolate spread, chocochips(around 1/2 cup), 2 tbsp hot water, 1 tbsp fresh cream.
Mix all of these together and pour it over your cake when it cools completely.