1 pkg. yellow cake mix
1 pkg. instant chocolate pudding
1 c. sour cream
4 eggs
1/2 c. oil
1/2 c. chocolate chips
1/2 c. walnuts, chopped
1 tbsp. vanilla

Combine and mix well, 5 minutes. Add rum (3 to 4 tablespoons). Put in a well greased tube pan. Bake at 325 degrees for 55 minutes.