1) In a small bowl add half cup boiling water, add cocoa then mix well and keep aside 2) Sieve flour and baking powder, keep aside 3) Beat sugar, oil and butter till its creamy, use beater 4) Add one egg at a time and beat well till all done 5) Add cocoa mixture with dry ingredients and fold in well 6) Pour on a medium sized greased baking tray, bake on 170°C 7) When cake is done let it cool a bit loosen the sides and remove on a rack 8) Let it cool down completely, then cut in half (horizontally) 9) Boil cream and cooking chocolate and whisk well 10) When it thickens remove from flame and beat till its thick, keep aside 11) Sprinkle expresso on both slices of cake 12) Lay one half on a platter or board, spread nutella on it, and place the other slice on top of it 13) Spread nutella on the entire cake 14) Pour the chocolate ganache on top of it to cover the entire cake 15) Decorate with walnuts, wholenuts and ferrero rocher