01 - Preheat oven to 300°F. Line a 9-inch round cake pan with parchment paper.
02 - In a bowl, combine all dried fruits, candied peel, and walnuts. Pour over rum or orange juice, mix well, and soak for at least 30 minutes or overnight for enhanced flavor.
03 - In a large bowl, cream softened butter with dark brown sugar until light and fluffy using an electric mixer or wooden spoon.
04 - Add eggs one at a time to the creamed mixture, beating well after each addition to ensure proper emulsification.
05 - Sift together flour, baking powder, salt, and all spices to ensure even distribution.
06 - Gradually fold the dry ingredients into the wet mixture, mixing gently to maintain airiness.
07 - Incorporate the soaked fruits and nuts along with any residual soaking liquid, then fold in the orange and lemon zest until evenly mixed.
08 - Pour the batter into the prepared cake pan and level the surface with a spatula.
09 - Bake for 1 hour 30 minutes, or until a skewer inserted in the center comes out clean.
10 - Allow the cake to cool completely in the pan before removing. Wrap in parchment and foil to retain moisture.