Preheat oven to 325 degrees F (165 degrees C). Grease and flour a 10 inch Bundt pan. Sprinkle chopped nuts evenly over the bottom of the pan. In a large bowl, combine cake mix and pudding mix. Mix in the eggs, 1/2 cup water, oil, and 1/2 cup rum. Blend well. Pour batter over chopped nuts in the pan. Bake in the preheated oven for 60 minutes, or until a toothpick inserted into the cake comes out clean. Stick holes all over the top of the cake and pour the glaze over. Allow the cake to sit and cool in the pan, while it absorbs the glaze. When cool, place a plate on top of the cake and holding the plate tight against the cake pan, flip the cake upside down. Enjoy!
For the Glaze
To make the glaze: in a saucepan, combine butter, 1/4 cup water, and 1 cup sugar. Bring to a boil over medium heat and continue to boil for 5 minutes, stirring constantly. Remove from heat and stir in 1/2 cup rum.