Preheat oven to 350F. Line 12 muffin cups with paper liners.

In a mixing bowl, whisk together flour, baking powder, baking soda, and salt until no lumps remain.

In the bowl of a stand mixer fitted with a paddle attachment, beat together vegetable oil and sugar until light and fluffy. Beat in bananas, egg, vanilla, and milk until thoroughly mixed. Add dry ingredients and beat until just combined. Use a rubber spatula to fold in chocolate chips.

Divide the mixture among the 12 muffin cups. Bake for 20 - 22 minutes, or until a toothpick inserted into the center comes out clean.

Cool completely on a wire rack before serving.