I got a recipe off the radio for pumpkin muffins. Can of pumpkin, one box spice cake mix. Nothing else. But I decided to add a egg to help it a little. Recipe was originally for muffins, 350 for about 25-30 minutes. delicious. So, had some ripe bananas, decided to try them. Mashed them up, added egg to them and made a banana spice cake. 350 for 35-40 minutes.
Have also done it with a can of applesauce, box of spice cake mix and one egg. Used a carrot cake once too. Was pretty good. Can toss in 1/2 cup raisins, or nuts or both. Be creative. I put mine in cake pan, smaller than a 9x13 but not the square one. Can also put in large loaf pan. This is very versitile and good. Try any kind of cake flavor. I prefer Duncan Hines myself. Creme cheese frosting. WOW! But if I put raisins in it, I don't touch it. DH takes care of it.