Preheat your fan forced oven to 180ºC. Grease 3 x 8” cake tins and line bases.
Sift the flour, salt, bicarbonate of soda and cocoa into a large bowl and put to one side. Pour the oil into the bowl and add the granulated sugar. Beat with electric mixer on a low speed until pale. Add the eggs, beating them in one at a time, and then mix in the red food colouring and vanilla extract.