Sift 300g (10 1⁄2 oz) flour and the salt into a large bowl. Add the yeast and sugar, then mix. Make a well in the centre and add the warmed milk, butter and egg. Stir the mixture until it is well combined and leaves the sides of the bowl cleanly. Add the remaining cake ingredients, except the marzipan, then knead for about 10 minutes on a surface dusted with some of the remaining flour until springy and elastic.