Measure 280 g of the rum-soaked fruit mixture, then strain and set aside.

Put the 50 g sugar in a pan and heat without water until it melts and turns dark brown. Remove from the heat and carefully add the 30 ml water a little at a time, as it will sputter. Stir to dissolve the caramel, returning briefly to gentle heat if necessary. Cool completely.

Preheat the oven to 180°C in conventional mode, fan off. Grease and line the base and sides of an 18 cm (7 inch) round metal cake tin, at least 7 cm deep. Bake on the middle shelf.

Mix all the dry-mixture ingredients. Take 2 tbsp from this measured mixture and toss it with the strained fruits. Keep the rest for the batter.

Cream the butter and dark brown sugar until pale and light, preferably with an electric whisk.

Mix in the vanilla, optional molasses and cooled caramel. Add the eggs one at a time, whisking after each addition. A slightly curdled appearance at this stage is all right.

Fold in the remaining dry mixture. Add the coated fruits and walnuts and fold gently until combined. Avoid overmixing.

Transfer to the prepared tin, filling no more than two-thirds of its height, and level the top. Reduce the oven to 160°C conventional for baking. Bake for around 50 minutes, beginning to check at 45 minutes. A skewer inserted into the centre should come out without wet batter. Continue baking as needed, checking at short intervals. Loosely cover the top with foil if it browns before the centre is done.

Allow the cake to cool enough to unmould, then brush with dark rum. Once completely cool, keep covered between brushings. Brush once a day for at least 2–3 days before serving.

Enjoy a slice with coffee or port wine.