Place the sultanas and currants in a bowl and warm in an oven or microwave. Add the rum, mix well and leave to soak.
Add the yeast to the milk, mix and leave for 10 minutes to allow the yeast to start working.
In a large bowl mix together the flour, salt, sugar and spices. Make a well in the centre.

Add the yeast/milk mixture then gradually incorporate enough flour from the side to make a thick batter in the middle. Flick a little flour from the side to just cover the batter.
Cover the bowl and leave in a warm place for 30 minutes.

Prepare the filling by mixing together the ground almonds, caster sugar and icing sugar.
Add the lemon juice and just enough beaten egg to make a firm paste.
Knead the paste well for a couple of minutes to ensure it is well mixed then roll out to a sausage about 20 cm (8") long. Cover and put to one side.

Return to the dough: Add the melted butter and beaten egg. Mix to a firmish dough, adding a little extra milk or beaten egg as necessary.
Turn the dough out onto a surface and knead for 10 minutes.
Place the dough in a lightly-greased bowl, cover and leave in a warm place to allow the dough to double in size.

Turn the dough out and knock back. Sprinkle on the brandy-soaked fruit, mixed peel and almonds. Roll up and knead for 2-3 minutes to distribute the fruit and nuts.
Flour the surface well and roll the dough out to 30 cm x 23 cm (12"x 9").

Place the roll of almond paste on the dough and fold over to cover. The top half should not completely cover the bottom half. The top edge should be slightly in from the bottom edge.
Transfer to a lightly-greased baking tray, place in a large plastic bag and leave to prove for about 1 hour.

Bake at 180°C/360°F fan oven, 200°C/400°F conventional oven for 25-30 minutes.
Brush with melted butter while hot and leave to cool.
Finally, dust with icing sugar.

#Notes:

You can cover this with fondant icing, royal icing or a frosting if you wish. You can also dust with cinnamon or drizzle over a thin glacé icing.