Prepare the Batter: Mash the ripe bananas in a large bowl until smooth. Add the eggs and mix well. Gradually add the cake mix, stirring until well combined. If using, fold in any optional add-ins like nuts or chocolate chips.
Bake the Banana Bread: Preheat your oven to 350°F (175°C). Grease two small loaf pans. Pour the batter evenly into the pans and bake for about 40 minutes, or until a toothpick inserted into the center comes out clean.
Cool and Serve: Allow the bread to cool in the pans for a few minutes before transferring to a wire rack to cool completely. Slice and serve, or wrap and freeze one loaf for later.