Heat oven to 350 °F (180 °C).

In a mixing bowl, whisk together oil, sugar and egg. Stir in mashed bananas and half the package of chocolate chips.

Combine flour, baking soda, salt and cinnamon. Stir into banana mixture just to moisten.

Spoon into 12 greased muffin cups. Sprinkle remaining chocolate chips evenly over top.

Bake for 15 to 20 minutes.