I got some saffron for Christmas. I love grocery items as gifts - the sort of things that are useful but a little luxurious, that you might not include in your regular weekly shop. Saffron, which costs a lot for a little, falls squarely into this category. So when a friend had a birthday recently, I was ready with a cake. Saffron is a subtle flavour so know this recipe will still work really well without it. But what it does offer is an enhancement of colour - a warm glow that suffuses the cake. Its fine filaments are flecked through it too, little quivers of colour. Without saffron, what you get is a great everyday orange cake, easily made with ingredients you're likely to already have on hand. But saffron makes it just a little bit special, which is what birthdays - and Christmases - are all about after all.