Grease and flour cake pan. Sprinkle nuts on bottom of pan, pour batter over nuts. Bake 1 hour at 325F.
Glaze: Mix together margarine, water and rum and boil to a light syrup -- 4 minutes. Add 1/2 cup rum. Punch holes in cake. Drizzle glaze over it.
[* -- Its exceptionally hard these days to find yellow cake mix without the pudding included as part of the mix. Assuming that's what you'll find, you can exclude the additional pudding]