The following recipe from Delia Smith is my personal favorite.

450g currants
175g sultanas
175g raisins
50g chopped glacé cherries
50g mixed chopped candied peel
100ml brandy
225g plain flour
¼ teaspoon nutmeg, freshly grated
½ teaspoon ground mixed spice
225g soft dark brown sugar
50g chopped almonds
1 dessertspoon black treacle
225g very soft butter
5 medium eggs
Grated zest of 1 lemon
Grated zest of 1 orange
½ teaspoon salt
Armagnac or brandy, to feed the cake

To decorate:
1 lb marzipan
1 lb ready-to-roll icing
1 heaped tbsp apricot jam
1 tbsp brandy

1. Preheat the oven to 140C, gas mark 1.
2. Now all you do is sift the flour, salt and spices into a very large roomy mixing bowl then add the sugar, eggs and the soft butter and either whisk or beat with a wooden spoon until everything is light, pale and fluffy. Now gradually fold in the pre-soaked fruit mixture, chopped nuts and treacle and finally the grated lemon and orange zests.
3. Next, using a large kitchen spoon, transfer the cake mixture into the prepared tin, spread it out evenly with the back of the spoon and, if you don’t intend to decorate the cake with marzipan and icing, lightly drop the blanched almonds in circles over the surface.
4. Finally cover the top of the cake with a double layer of baking parchment with a 50p-size hole in the centre (this gives extra protection during the long slow cooking). Bake the cake on the lowest shelf of the oven for 4 hours until it feels springy in the centre when lightly touched. Sometimes it can take 30–45 minutes longer than this, but in any case don’t look for 4 hours.
5. Cool the cake for 30 minutes in the tin, then remove it to a wire rack to finish cooling. When it’s cold, feed it by making small holes in the top and bottom with a cocktail stick and spooning in a couple of tablespoons of Armagnac or brandy, then wrap it in double baking parchment secured with an elastic band and either wrap again in foil or store in an airtight tin. You can now feed it at odd intervals until you need to ice or eat it.

To decorate, warm the apricot jam and brandy in a small saucepan, stirring well. Brush this mixture all over the cake. Roll out circular pieces of marzipan then icing to fit the top of the cake. Finish off with cake decoration of your choice.