Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a mixing bowl, mash the ripe bananas until smooth and creamy.

Combine the mashed bananas, vegetable oil, and light brown sugar in a large bowl, stirring until glossy and well-blended.

Gently stir in the egg yolk and vanilla extract until evenly incorporated.

In a separate bowl, whisk together the all-purpose flour, baking soda, ground cinnamon, and salt.

Gradually mix the dry ingredients into the wet mixture, stirring until no flour streaks remain.

Gently fold in the chocolate chips until evenly distributed throughout the dough.

Cover the dough and let it rest for 15 minutes.

Scoop the dough into 1-inch balls, placing them two inches apart on the prepared baking sheet.

Bake for 10-11 minutes, until edges are set and centers look slightly underbaked.

Allow cookies to cool on the baking sheet for a few minutes before transferring to a wire rack.