Pre heat oven to 180c.prepare your baking tin

Sift the flour,cocoa and salt together In a bowl and set a side

In separate bowl,beat butter until soft,add sugar and beat until fluffy

Add the egg,thoroughly mix,add the vanilla essence and mix

In a jug,add the food colour to the buttermilk and stir till fully mixed

Add the flour and buttermilk in starting and ending with the flour to the butter mixture

In a small cup combine the vinegar and baking soda,allow the mixture to fizz and then quickly fold into the cake batter.speed is of importance.

Pour the batter into a tin and level,straight to the preheated oven

Bake for 40mins,or till the inserted skewer comes out clean