Preheat oven to 325 degrees.
Spray pan with nonstick cooking spray.
In a medium bowl, combine cake mix and cinnamon and blend together.
In a separate bowl, mash bananas until creamy. Add eggs and blend together with a fork.
Add banana mixture to dry ingredients and combine.
Add soda and mix well.
Fold in chopped pecans.
Pour into prepared 9x13 pan and bake for about 35 minutes or until a toothpick comes out clean.