Sprinkle the nuts evenly around the bottom of the bundt pan.
Mix the remaining cake ingredients together: cake mix, pudding mix, eggs, 1/2 cup water, vegetable oil and 1/2 cup rum.
Pour batter into the bundt pan over the nuts.
Bake for 1 hour or until a toothpick inserted into the cake comes out with just a few crumbs.
Cool the cake, removing from the pan after 15 minutes and cooling the rest of the way on a cooling rack.
Prepare the glaze by melting the butter in a saucepan.
Stir in the water and sugar, heating over medium high until mixture comes to a boil.
Boil for 5 minutes, stirring constantly.
Remove the glaze from the heat and stir in rum.
Use a pastry brush to spread the glaze over cooled cake, concentrating on the top (where the pecans are), but also brushing over the sides and inner ring. It will take multiple applications to use up the whole saucepan of glaze, but it is worth the extra time! Use every drop!