Preheat oven to 350 degrees.
Grease and flour two 9 inch cake pans.
In large bowl combine cake mix, 1 package pudding, eggs, 1/2 c rum, cold water, and oil.
Blend well, then beat at medium speed for 2 minutes.
Turn into prepared pans.
Bake 30 minutes or until toothpick inserted in center comes out clean.
Do not underbake.
Cool in pans for 10 minutes.
Remove from pans and cool completely on wire racks.
Combine milk, 1/4 c rum, 1 package pudding mix, and topping mix.
Blend well at high speed for 4 minutes, until light and fluffy.
Split layers in half horizontally.
Spread 1 cup filling between each layer and over top of cake.
Keep cake chilled. Serve cold.