1 box orange-flavored cake mix
2 tbsp butter
1/3 cup (packed) brown sugar
1/2 cup finely chopped walnuts or pecans
1 1/2 cups sour cream
Preheat oven to 350 degrees. Grease and flour a 12 cup Bundt pan. (If you don't have a Bundt pan, you can use a 10-inch tube pan.) Set pan aside.
In a small bowl measure out 1/4 cup of the dry cake mix; cut in the butter. Stir in the nuts and brown sugar; set aside.
In a large mixer bowl, blend the remaining cake mix, eggs, and sour cream on medium speed of electric mixer; scrape bowl frequently. This is a thick and slightly lumpy batter.) Pour half of the batter into the prepared pan. Sprinkle the sugar and nut mixture over the batter in pan. Gently spoon the remaining batter over the filling. Bake at 350 degrees for an hour or until done. Cool for 10 minutes; remove from pan and cool completely on a wire rack.