Preheat oven to 400°F.
Grease two 12-cup muffin tin or line with paper liners.
In a large bowl, mix together the spice cake mix, pumpkin puree, milk, and chocolate chips.
If desired, add the mashed banana or applesauce for extra-moist muffins.
Divide the batter evenly between the muffin cups.
Bake for 12–15 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.
Cool for several minutes before removing from the pan.
Tip: Sprinkle a few extra chocolate chips on top of the muffins before baking for an irresistible bakery-style finish!