1. Sift the cocoa powder, flour, baking powder and soda bi-carbonate.
2. Combine all the ingredients together with 1/2 cup (100 ml.) of water in a bowl and mix well using a whisk.
3. Pour this mixture into a greased 150 mm. (6 inches) diameter baking tin after greasing it.
4. Bake in a pre-heated oven at 180 deg C (360 deg F) for 20 minutes or till a knife inserted into the cake comes out clean.
5. Unmould and cool on a wire rack.

Courtesy: http://chefinyou.com/