1. Preheat the oven to 350°F/180°C and grease an 8 inch cake tin.
2. Sift the flour and cocoa powder into a bowl and add the sugar and salt.
3. Add the oil, a little at time, mixing well to avoid lumps. Add the soy milk and vanilla extract and mix thoroughly.
4. Gently pour into the cake tin and spread out until even. Bake for about 15 minutes and check with a knife (the knife should come out clean when inserted into the brownies 2cm from the edge).
5. Allow to cool in the tin for a few minutes before cooling on a wire rack.