Good-quality marzipan is vitally important to this cake, which we call ‘kransekage’, and the taste will reflect the quality. The best marzipan contains 60 per cent almonds, with no artificial flavours or colours. These cakes are supposed to be soft in the centre, so take care not to over-bake them. It may be unusual to measure egg whites in a jug, but it’s necessary here, as the volume of them is vital.