Preheat the oven to 180°C. Grease and line 2 x 20cm cake tins.
Cream the butter, sugar and eggs until light and fluffy.
In a separate bowl mix the vanilla extract, cocoa powder and red food colouring into a paste. Add the paste to the creamed mixture.
Add half the buttermilk and mix until combined, followed by half of the flour and baking powder. Mix until incorporated and then add the remainder of the buttermilk and flour and mix thoroughly.
Add the salt, bicarbonate of soda and white wine vinegar and continue mixing for another 5 minutes until combined.
Pour the mixture evenly into the 2 cake tins.
Bake in the oven for 35-40 minutes or until a skewer comes out clean.
Allow the cakes to cool slightly in their tins before turning out onto a wire rack