Preheat oven to 425 degrees F and grease a standard 12 slot non stick muffin tin with cooking spray. Set aside.
In a large bowl, whisk together butter, sugar, egg, vanilla, and bananas.
Add in flour, baking soda, baking powder, cinnamon, salt, and chocolate chips, then use a rubber spatula to mix until *just* combined. Don’t over mix.
Use a 1/4 cup measuring cup to scoop the batter evenly into the prepared muffin tin.
Bake for 5 minutes at 425 degrees F.
Lower heat to 350 degrees F (keep muffins in oven) and bake an additional 10-15 minutes (mine took 12), or until a toothpick comes out practically clean.
Remove from the oven, cool slightly, then transfer muffins to a wire rack to continue cooling.