Preheat oven to 350°; butter an 8- or 9-inch flat-bottomed tube pan; dust with all-purpose flour, invert over the kitchen sink, and tap to remove excess.
To soften the raisins--place in a steam basket in a medium saucepan and steam for 1 minute over boiling water (do not submerge the raisins or they will absorb too much water).
Spread them out over several layers of paper towels and dry thoroughly.
Using a triple sifter, sift together the flour, baking powder, salt, and cinnamon; set aside.
Cut the butter into 1-inch pieces and place it along with the rinds in the bowl of an electric stand mixer fitted with paddle attachment.
Soften on low speed.
Increase speed to med-high and cream until smooth and light in color, about 1 1/2 to 2 minutes.
Add in sugar, 1 tablespoon at a time, taking 6-8 minutes to blend it in well; scrape the sides of the bowl occasionally.
Add in eggs, 1 at a time at 1-minute intervals, scraping the sides of the bowl again.
Blend in the vanilla.
Decrease mixer speed to low; add the dry ingredients in three additions alternately with the rum in two additions, mixing until incorporated after each addition; mix the batter for 15 seconds longer.
Remove bowl from mixer and fold in raisins with a rubber spatula.
Spoon batter into prepared pan; smooth the surface with the back of a tablespoon.
Center the pan on the rack and bake for 45-50 minutes, or until the cake is golden brown on top and begins to come away from the sides of the pan; or toothpick inserted into the center comes out dry.
Remove cake from oven; set on a cake rack for 10-15 minutes; invert cake onto a rack and remove the pan.
Turn cake top side up onto a second cake rack to cool at room temperature.
Cut a double thickness of cheesecloth to measure approximately 18 x 24 inches.
Saturate in 1/4 cup dark Jamaican rum; open the rum soaked cheesecloth and stretch flat on an 18-inch square of heavy-duty foil; arrange cake in the center of the cheesecloth.
Wrap the cloth over the cake by lifting the ends and bringing them to the center.
Then wrap tightly in foil; place the cake in a plastic bag and seal; let stand at room temperature overnight.
The following day, remove the foil and unwrap the cake; remoisten the cheesecloth with an additional 1/4 cup rum; rewrap the cake in the cheesecloth and foil and return to the plastic bag to age for 2-3 days or up to 10 days.
It is not necessary to remoisten the cheesecloth after the second day.
Wrap leftover cake in the cheesecloth; store in plastic wrap or foil at room temperature for up to 10 days.