Mash the bananas and set aside.
In a bowl, combine the mashed bananas, melted butter, and sugar.
Add the eggs and mix well.
Sift in cake flour, baking powder, cocoa powder, and salt, then mix.
Add chocolate chips and mix evenly.
Pour the batter into a pan and place banana slices on top.
Bake in a preheated oven at 180°C for about 40–50 minutes.