Preheat the oven to 350°F (175C).
Place bananas in a large bowl and mash.
To the mashed bananas add in the eggs, maple syrup, peanut butter, vanilla extract and milk and stir well to combine.
Add in the oat flour, cinnamon, baking soda and salt. Using a spatula, carefully mix until the batter is just combined. Be careful not to overmix.
Add the chocolate chips to the mixture and stir to combine.
Either use a nonstick spray to spray a 12-count muffin or use cupcake liners.
Divide the batter equally among muffin liners. Sprinkle chocolate chips and oat flakes onto each muffin.
Bake for 20 minutes, or until a toothpick inserted into the muffin comes out clean, with just a few crumbs attached.
Remove from the oven, and allow the muffins to cool for 5 minutes in the muffin tray, before transferring to a wire cooling rack and allowing to cool completely.