Sift the plain flour through a sieve into a large mixing bowl
Add the caster sugar, cocoa powder, baking soda, and bicarbonate of soda
Mix well with a spatula and transfer it into the food processor
Crack the eggs into the mixture, add the vanilla essence and the yogurt and mix roughly with a spatula before running the food processor to ensure that the loose flour doesn't fly all over the place. For the first 30 seconds, I lightly covered the chute of the processor with my palm to prevent the flour from flying out in a mist. Now, this is the reason I want a Kitchen Aid ;)
After an initial spin, use the blunt edge of the knife to scoop out what stuck to the walls of the processor and mix well with the cake batter.
Don't worry if you think the batter is very thick, another spin for about a minute should give you the required consistency to ''pour'' into the cake tins
Grease two removable base 8-inch tins with butter and equally divide the cake batter into each tin
Preheat the oven to gas mark 4/180°C/350ºF
Bake for 25 minutes and then test the center of the cake with a cake tester or thin skewer
My cakes were done in 25 minutes but you may need up to 30 minutes depending on the type of oven. The cakes rose beautifully but the top had cracks. The icing was there to save the day and make the cake look pretty
Remove cakes from the baking tray and leave to cool down on a wire rack