Preheat oven to 350F. Line a 9×5 loaf pan with parchment paper and set aside.
In a large bowl, whisk mashed bananas, sugar, oil, eggs, yogurt, and vanilla until smooth. In a separate medium bowl, whisk flour, cocoa, baking soda, and salt.
Add flour mixture and chocolate chips to liquid mixture, gently folding until batter is just combined.
Spread batter evenly in prepared pan. Optionally, top bread with a halved small banana and additional chocolate chips. Bake banana bread at 350F 55-60 minutes until a toothpick inserted in center comes out clean.
Cool banana bread completely on a wire cooling rack. Remove bread from pan and cut into slices for serving. Enjoy!