Preheat oven to 325F. Grease and flour 10" tube or 12-cup Bundt pan. Sprinkle nuts over bottom of pan. Mix all cake ingredients together. Pour batter over nuts. Bake 1 hour. Cool. Invert on serving plate. Prick top. Spoon and brush glaze evenly over top and sides. Allow cake to absorb glaze. Repeat till glaze is used up.
Glaze: Melt butter in saucepan. Stir in water and sugar. Boil 5 minutes, stirring constantly. Remove from heat. Stir in rum.
Optional: Decorate with border of sugar frosting or whipped cream.