Mash two of the bananas; stir in the orange juice. Coarsely mash, then stir in,
the two remaining bananas. Combine the banana mixture, Cool Whip and the dry pudding
mix. Set aside while preparing the cake.
Cut the cake lengthwise into three layers; drizzle with the banana rum. Spread
1/3 of the pudding mixture over the bottom layer; top with the second layer. Spread
with 1/3 of the pudding mixture; top with third layer. Spread with remaining pudding
mixture. Sprinkle with the chopped nuts if desired.
Chill for at least one hour
before serving. Garnish with banana slices if desired.