Heat oven to 160C/140C fan/gas 3.
Line a 900g/ 2lb loaf tin with greaseproof
paper. Place the flour, mixed spice,
caster sugar, zests, dried fruit and
a pinch of salt into a large bowl.
Melt the butter and 2 tbsp marmalade
in a saucepan, then stir in the milk. Pour
liquid into the dry ingredients, add the
white wine vinegar and mix well.
Pour the cake mixture into the lined
loaf tin and bake for 1 hr, or until an
inserted skewer comes out clean.
Meanwhile, make the glaze by
heating the remaining marmalade
with 2 tbsp water and the icing sugar
until bubbling and syrupy. When the
cake is cooked remove it from the
oven, pour over the marmalade
glaze, then sprinkle with demerara
sugar. Leave to coolin the tin.