3 medium large ripe bananas 1/2 cup unsalted butter melted 3/4 cup brown sugar 1 large egg 1 tsp vanilla extract 1 tsp baking soda 1/4 tsp salt 1 cup all purpose flour 1/2 cup cocoa powder (i used hershey's special dark) 1 cup (6 oz) semisweet or bittersweet chocolate chunks or chips 1/2 cup mini chocolate