Orange cake

Looking for a recipe for a nice layer cake to make as a birthday cake, I came across a recipe for an orange cake in the Primrose Bakery book, and couldn't resist giving it a try.  It looks so pretty - I love how the orange zest on top is dispersed by the icing dripping down the sides - and tastes delicious (even if I do say so myself!).  The use of orange zest (in the sponge and buttercream) and freshly squeezed orange juice (in the buttercream and icing) gives the cake a lovely flavour.  Certainly one I will be making again.