Combine the sultanas, raisins, cherries, currants and brandy in a large glass or ceramic bowl. Cover with plastic wrap and set aside, stirring occasionally, for 6 hours to macerate.
Preheat oven to 150°C. Brush a round 22cm (base measurement) cake pan with melted butter to lightly grease. Line the base and sides with 2 layers of non-stick baking paper to reach 6cm above the edge of the pan.
Use an electric beater to beat the butter and sugar in a bowl. Add the eggs, 1 at a time, beating well after each addition until combined (the mixture may curdle at this stage - this is due to the high proportion of eggs to butter and doesn't affect the result). Add the marmalade and beat until well combined. Add the combined flour and mixed spice, and fold until just combined. Stir in the sultana mixture. Spoon into prepared pan and smooth the surface. Tap the pan on the benchtop to settle the mixture. Arrange the almonds over the top.
Wrap the outside of the pan with 3 layers of newspaper, rising slightly higher than the baking paper. Secure with kitchen string. Bake, covering with foil if necessary to prevent overbrowning, for 3 1/2 hours or until a skewer inserted into the centre comes out clean.
Pour the extra brandy over the hot cake. Wrap the pan in a clean tea towel and set aside overnight to cool completely. Serve.
