To make Caribbean black fruitcake, coarsely chop 3/4 cup of candied orange peel, 1 3/4 cups of prunes, 1 1/2 cups of raisins, 1 3/4 of dried cherries and 1 3/4 whole raw almonds. Use a 3-quart container with a lid to mix the fruit and almonds with 1 1/2 cups of ruby port, 1 1/2 cups of dark rum and 1 1/4 cups of currants. Cover the container with the lid, making sure it fits tightly.
Store the fruit and almond mix in a cool, dark place for one week.
Preheat the over to 300 degrees Fahrenheit with a rack in the middle, and prepare two 9-by-5-inch loaf pans by coating them with butter.
Combine 2 cups of all-purpose flower, 2 teaspoons of kosher salt, 1 tablespoon of baking powder, 1/2 teaspoon of ground cinnamon, 1/2 teaspoon of ground clove and 1/2 teaspoon of ground nutmeg. Whisk until there are no lumps left.
Beat 1 pound of unsalted butter at room temperature and 2 1/4 cups of brown sugar in a stand mixer with a paddle attachment at medium speed for three minutes. Add 6 large eggs, one at a time. Let each egg fully mix with the other ingredients before adding the next. Add 2 teaspoons of vanilla extract. Set the mixer to slow speed.
Add 3/4 cup of burnt sugar syrup and the fruit mix to the flour mix. Once the ingredients are fully integrated, put one-half of the batter onto each loaf pan.
Bake both pans for about two hours. Stick a tester or knife in the middle. If it comes out clean, the cake is ready. Cool down the pans on a wire rack for 30 minutes. Remove them from the pans, and brush them with 2 tablespoons of dark rum.