Preheat the oven to 300°F. In a large bowl, combine the dried fruit and rum; toss and set aside to soak.
Grease a Bundt or tube pan well, or line a few loaf pans with parchment.
Place the sugar in a small saucepan or skillet set over medium-high heat and cook, swirling the pan as the sugar melts, until it turns deep golden. Remove from the heat and gently stir in 2 Tbsp water — it will splatter. Set aside.
In a large bowl, beat the butter and sugar for a few minutes, until light and creamy. Beat in the molasses and orange and lemon zest and juice.
In a medium bowl, stir together the flour, baking powder, baking soda, salt, cinnamon, allspice and nutmeg. Add the flour mixture to the butter mixture in 3 parts, alternating with the wine or juice in 2 parts. Stir in the fruits (with their juices), the caramel sauce and nuts and scrape into the prepared pan.
Bake for 2½-3 hours, until dark golden and set. If the cake is darkening too quickly on top, cover it loosely with foil for the last 30-60 minutes. Cool in the pan on a wire rack, then invert onto a plate.
Store well wrapped at room temperature.