Step #1 Grease & lightly flour eight 1-c fluted tube pans or six 4-1/2x2-1/2x1-1/2-inch individual loaf pans & set pans aside.
Step #2 In a medium bowl mix flour, baking powder, & baking soda; set aside.
Step #3 In a large bowl beat butter with an electric mixer on medium to high speed for 30 seconds, add brown sugar; beat until mixd.
Step #4 Add eggs, one at a time, beating on medium speed until mixd (The batter may appear curdled).
Step #5 Combine 1/4 c rum or pineapple juice, ginger, 1/4 c pineapple juice, the corn syrup, & vanilla.
Step #6 Add flour mixture & rum mixture alternately to butter mixture, beating on lowish speed after each addition just until mixd.
Step #7 Fold in fruit bits & nuts.
Step #8 Spread batter in prepared pan.
Step #9 Bake in a 325F degree oven for 20 to 25 mins for fluted tube pans or 30 to 35 mins for loaf pans or until a toothpick inserted into centers comes out clean.
Step #10 Cool cakes in pans on wire racks for 10 mins.
Step #11 Remove from pans; cool at least 1 hr on racks.
Step #12 Poke holes in cakes using a wooden toothpick or bamboo skewer.
Step #13 Soak eight or six 8-inch-square pieces of double thickness 100-percent cotton cheesecloth with the 1/3 c rum or pineapple juice & wrap each cake in rum- or juice-soaked cheesecloth.
Step #14 Wrap each cake tightly in foil wrap or seal in a plastic bag.
Step #15 Chill in refrigerator for 24 hrs.
Step #16 Remove foil wrap or remove cakes from bags; drizzle with 1/4 c rum or pineapple juice.
Step #17 Rewrap with foil wrap or return to plastic bags & put in the fridge at least 24 hrs.
Step #18 Remove cheesecloth before serving.
Step #19 If desired, sprinkle with sifted powdered sugar.
Step #20 Makes 6 or 8 cakes (24 servings).
Step #21 Make-Ahead Tip: Prepare Tropical Fruit Cake as directed through until the 24 hr chill, except put in the fridge up to 5 days.
Step #22 (Or prepare Tropical Fruit Cakes as directed through up to 24 hr chill, except do not sprinkle with powdered sugar.
Step #23 Place in self-sealing freezer bags.
Step #24 Seal, label, & freeze up to 3 months.
Step #25 )
To serve, thaw frozen cakes in freezer bags in the refrigerator overnight.