Pre-heat oven to slow (150 degrees celsius or 140 degrees celsius, fan-forced)
Line a round cake tin (approx 24cm in diameter) with 3 layers of baking paper.
Cream butter and sugar until the mixture is pale and creamy. Beat on med-high if using a stand mixer.
Add eggs and beat again (on med if using a stand mixer).
Sift flour, salt and nutmeg.
Add dry ingredients to mixture alternately with the fruit and nuts, stirring to combine.
Mix hot milk with vinegar and rum. Add bicarb soda and dissolve. Add to the mixture and stir well to combine.
Pour mixture into cake tin and use the back of a dessertspoon if necessary to spread the mixture evenly in the tin.
Bake in a slow oven for 2 1/2 hours or until golden in colour and a skewer inserted into the middle of the cake can be removed without any cake sticking to it.
Remove the cake from the oven and brush the top with a little extra rum or brandy. Place foil over the top of the cake and then wrap in a clean towel.
Leave the cake to cool for at least 24 hours, preferably a few days.
Remove the cake from the tin and wrap in foil and a clean tea towel. Store in a cool, dark place for up to 3 weeks. Store in the fridge for up to 2 months and in the freezer for a year. (Always use your own judgment though, these times are a guide only).