10½ tablespoons unsalted butter, softened, plus more for greasing the pan
¼ cup unsulphured molasses (not blackstrap)
1 large egg
⅓ cup plus 1½ tablespoons all-purpose flour
1 teaspoon freshly ground black pepper
1 teaspoon ground cinnamon
¾ teaspoon kosher salt
¼ teaspoon baking soda
¼ teaspoon freshly grated nutmeg
¼ teaspoon ground allspice
Directions
Combine the rum and cherries in a small bowl and let stand for at least 4 hours, or overnight if you prefer. Drain the cherries, reserving the rum, and transfer to a bowl along with the walnuts, candied orange and candied ginger.
Preheat the oven to 325°F. Grease a loaf pan and line with parchment paper. In a stand mixer fitted with the paddle, cream ½ cup plus 1½ tablespoons of the sugar with the butter and molasses on medium speed until lightened in color and fluffy, about 2 minutes. Add the egg and continue mixing until combined, about 30 seconds. Turn the mixer off, scrape the paddle and bottom and sides of the bowl with a rubber spatula, then mix for 15 seconds until smooth.
In a medium bowl, whisk the flour with the pepper, cinnamon, salt, baking soda, nutmeg and allspice. Using a large rubber spatula, fold the dry ingredients into the butter mixture until almost combined. Add the walnuts and dried fruit and mix until completely incorporated. Scrape the batter into the prepared loaf pan and bake until a toothpick inserted into the center of the cake comes out clean, about 55 to 65 minutes.
While the cake is baking, combine ½ cup of the reserved rum with 1 tablespoon water and the remaining ½ cup sugar in a small saucepan over low heat, stirring to dissolve the sugar. When the cake is done, transfer the pan to a rack and brush with all of the rum syrup. Let the cake cool completely, then remove from the pan and serve, or wrap in plastic wrap and store at room temperature for up to 2 weeks.