Red Velvet Cake is, in some ways, the supermodel of the cake world. It is very striking - a real showstopper - but artificially so. It's good looks can usually be attributed to copious amounts of food colouring. Not natural food colouring - the hard, E number, stuff. This apparently wasn't always the case. The cake initially owed it's reddish hue to a chemical reaction between the cocoa powder, bicarbonate of soda and buttermilk. Adams extract company very cleverly marketed their red food colour with tear-off recipe cards for Red Velvet cake and the rest, as they say, is history.