My daughter had us over for dinner, and served this "mysterious" cake for dessert. We thought it was very good - and she laughed and said it only had 2 ingredients in it. Of course I got her "recipe" - and have had fun with different flavors.
Preheat oven to 350. Grease and flour a bundt pan. Blend together with mixer, in a large bowl the can of pumpkin and cake mix. Batter will be very thick. Beat for about two minutes until thoroughly mixed. Pour into cake pan. Bake 40-45 minutes until cake tests done.
Allow cake to cool about 10 minutes before turning onto serving plate. Can be dusted with powdered sugar or glazed. Cake will not rise as much as a "regular" bundt cake, but will be very moist and delicious. It's fun to experiment with other cake mix flavors -- and to have people guess what the ingredients are.