Preheat your oven to 350°F (175°C) and prepare a muffin tin by lining it with paper liners or greasing it with butter to ensure the muffins don’t stick.
Mash the ripe bananas in a large bowl, leaving a few lumps for texture. The riper the bananas, the sweeter and more tender your muffins will turn out.
In the same bowl, add peanut butter, vegetable oil, brown sugar, and granulated sugar. Whisk until smooth, creating a rich peanut butter base.
Add the eggs one at a time, mixing well after each, then stir in the vanilla extract to bring everything together.
Pour in the milk and stir gently until fully combined, creating a smooth batter.
In a separate bowl, sift together the dry ingredients, flour, baking powder, baking soda, salt, and cinnamon (optional).
Add them to the wet mixture and stir until just combined, avoiding overmixing.
Fold in the chocolate chips gently, ensuring they’re evenly distributed without overworking the batter.
Spoon the batter into the muffin tin, filling each cup approximately two-thirds of the way.
Bake for 18 minutes or until a toothpick comes out clean with a few crumbs. Enjoy!