Scald the milk i.e heat until steaming but just below boiling, let cool until body temperature.
Meanwhile, beat the egg yolks with the whole egg. Set aside
Cream the butter with caster sugar and then beat in the egg in several additions. Add the lemon zest.
In a large separate bowl sift in the flour and salt. Crumble over the yeast and add half the milk as well as the sugar, butter and egg mixture. Combine with a cutlery knife. If the mixture is still dry or patches of flour are left add milk until you have no patches of flour left.
Turn out onto the work surface and knead until you have a smooth and shiny dough. Return to the now cleaned bowl, cover with clingfilm and leave to rise in a warm place (around 1-2 hours)
Meanwhile soak the sultanas in the rum.
Heat the oven to 200°C/180°C fan. Lightly grease the bund tin and then sprinkle with the sliced almonds.
Turn out the dough onto your surface again and knock back (i.e. knead briefly to redistribute the air bubbles). Knead in the chopped almonds and soaked sultanas.
Shape the dough into a sausage shape and close the ends to form a ring, roughly the diameter of the bund tin. Place the dough into the tin, cover with cling film and leave to rise again until roughly doubled in size (about 30-45 min)
Bake for 45 min to 1 hour on the middle shelf. Turn out and leave to cool then sprinkle with icing sugar.