In a large saucepan, combine the pudding mix and milk. Bring to a boil over medium heat, stirring constantly.
Remove from the heat; stir in dry cake mix. Pour into a greased 9x13 pan. Sprinkle with butterscotch chips and pecans. Bake at 350 degrees F for 35 to 40 minutes or until a toothpick inserted in the center comes out clean.
I made this cake for a church event, it was a huge hit. Have had requests for recipe, and also have made the cake again for a friend that loved it. It is easy, quick, and delicious. I would definitely recommend this cake to a butterscotch lover! Try it, you won't regret it!!!