Preheat oven to 350F. Line a 12 cup muffin or jumbo muffin tin with muffin liners.
In a medium bowl, sift together flour, baking soda, baking powder, salt, and cinnamon. Set aside.
In a medium bowl, mash 3 ripe bananas. Add brown sugar and whisk until smooth.
Add peanut butter, sour cream, and vanilla. Whisk until smooth. Add in both eggs and whisk until combined.
Add in ⅓ of dry ingredients and ½ of the milk and whisk until combined. Add in the next ⅓ of dry ingredients and rest of the milk and whisk again. Finish with the last of the dry ingredients and whisk until smooth.
Fold in regular chocolate chips and mini chocolate chips.
Use an ice cream scoop and fill muffin liners until ¾ full. Sprinkle mini chocolate chips on top and gently pat them into the batter.
For regular sized muffins bake for 18-24 minutes. For jumbo muffins bake for 28-32 minutes. The muffins are done when the tops are golden brown and when a tooth pick is inserted it comes out clean.
Let the muffins sit in the tin for 10 minutes before transferring to a cooling rack. Let cool completely before storing them.