Put the raisins in a bowl and pour the rum over top. Cover and let sit for at least an hour or overnight, stirring occasionally.
Preheat the oven to 350°F (175°C).
Butter a 12 cup Bundt pan.
Sift the flour, baking soda, salt and nutmeg together into a large bowl.
Cream the butter and sugar together using an electric mixer.
Beat in the beaten eggs along with a tablespoon of the flour.
Add the bananas and beat in on low speed.
Add the buttermilk and flour alternately in four additions, beginning with the flour and ending with milk
Remove the mixing bowl from the electric mixer and thoroughly fold in the raisins and any remaining rum with a wooden spoon.
Transfer the batter to the prepared Bundt pan.
Bake for 50 to 60 minutes, or until a skewer inserted in the cake comes out clean.
Cool in the pan for 15 minutes, and then remove the cake carefully from the pan. Cool completely on a wire rack.
To make the glaze, add the rum gradually (a tablespoon or less at a time) to the icing sugar to make a thick glaze. You may not need all the rum. Beat in the honey until the glaze is thick and glossy. Drizzle over cooled cake.