For the icing
Preheat the oven to 180°C, gas mark 4. Line a 20cm x 30cm baking tin with baking paper.
Beat the eggs and sugar together until light – approx. 3-5 minutes. Add the rest of the ingredients. Mix until smooth – don’t overmix. Pour into the tin and bake for 50-55 minutes or until a skewer comes out clean. Allow to cool in the tin.
To make the icing, heat the coconut milk and add the saffron. Allow to infuse for 15 minutes.
Meanwhile, in the bowl of a stand mixer fitted with a paddle attachment, beat the butter and icing sugar until smooth. Pour in the coconut milk, spices and salt. Beat until smooth, scraping down the sides. Increase the speed to high and continue to beat until light and fluffy.
Spread the frosting onto the cake and serve.