1 cup chopped walnuts (optional)
1 (18.25 ounce) package yellow cake mix
1/2 cup dark rum
4 eggs
1/2 cup water
1/2 cup vegetable oil
1 (3.5 ounce) package instant vanilla pudding mix

Glaze
1/2 cup butter
1/8 cup water
1/2 cup granulated sugar
1/4 cup rum
Directions

Preheat oven to 325 degrees F (165 degrees C). Grease and flour a 10 inch tube or Bundt pan. Sprinkle nuts over the bottom of the pan.
Mix together the cake mix, 1/2 cup dark rum, eggs, 1/2 cup water, oil, and vanilla pudding mix. Pour batter over the nuts in the pan.
Bake for 1 hour. Cool, and invert cake on a serving plate. Prick the top of the cake.
To Make The Glaze: Melt the butter in a saucepan. Stir in 1/8 cup water and the 1/2 cup sugar. Boil for 5 minutes, stirring constantly. Remove glaze from heat, and stir in 1/4 cup rum. Drizzle and smooth evenly over the top and sides.