Preheat the oven to 350°F (175°C) and grease a 9x5-inch loaf pan with butter or non-stick spray.

In a mixing bowl, whisk together the flour, baking soda, and salt until evenly combined.

In another large bowl, melt the butter and let it cool slightly. Whisk in the vegetable oil and granulated sugar until smooth.

Incorporate the eggs one at a time, followed by the vanilla extract and then fold in the mashed bananas.

Gently add the dry ingredients to the wet ingredients, mixing just until combined.

Fold in the chocolate chips, ensuring they are evenly distributed throughout the batter.

Pour the batter into the prepared loaf pan and smooth the top.

Bake for 60-70 minutes until golden brown and a toothpick inserted comes out clean.

Remove from the oven, cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.