Preheat the oven to 350F
In a bowl add the bananas and mash them until they are smooth. Add in the melted butter and then stir until well combined.
Add in the sugar, egg, vanilla, baking soda, salt and flour, and stir until the batter is smooth.
Let the batter rest for at least 15 minutes, to let the whole wheat flour to fully hydrate.
Stir in the chocolate chips gently. Be careful not over mix the batter. Pour the batter into a greased loaf pan. Top with additional chocolate chips.
Bake for 50 minutes to an hour, or until a toothpick comes out clean.
cool completely before serving.