preheat the oven to 325°. Butter an 11 x 7" baking pan. Line with parchment paper, letting the edges overhang.
Mix the flour, baking powder, cinnamon, cloves, cardamom, and salt in a medium bowl. Bring the dark raisins, golden raisins, and rum mixture to a boil in a small pan. Remove from heat and set aside for 15 minutes to allow the raisins to soak up the liquid. Coarsely chop the walnuts and almonds. Stir the raisin mixture, cherries, walnuts, and almonds in a large bowl. Fold in 1 tablespoon of the dry ingredients. Melt the chocolate in a double boiler over barely simmering water.
Beat the butter and Brown sugar in a large bowl with an electric mixer at high speed until creamy. Add the orange zest and melted chocolate. Add the eggs one at a time, beating until just blended after each addition. Use a large rubber spatula to fold in the remaining mixed dry ingredients, followed by the raisin mixture and orange juice. Spoon the batter into the prepared pan, smoothing the top. Bake until a toothpick inserted into the center comes out clean, 60 to 75 minutes. Let cool completely before cutting.