Preheat oven to 350°F. Either spray bundt pan with butter Pam or grease with butter. Add chopped walnuts to bottom. Mix cake mix, Jell-O instant pudding, oil, water, rum, and beaten eggs together for 3-5 minutes.
Put batter in bundt pan and bake for 50 minutes.
In small sauce pan, melt butter and sugar. Add water, boil for 5 minutes while whisking. Take off stove and add 1/4 cup of rum. When cake cools, flip over and take out of bundt mold. Poke holes in cake and pour glaze over cake. Keep basting cake with glaze that runs to bottom. Put on clean plate when finished.