Preheat the oven to 350°F and line a 12-cup muffin tin with paper liners.
In a large bowl, whisk together the flour, baking powder, baking soda, ground cinnamon and salt.
In a separate medium bowl, whisk together the egg and brown sugar.
Mix until well combined.
Add and stir together the mashed bananas, peanut butter and plain yogurt.
Mix until smooth.
Stir in the vanilla extract.
Pour the wet ingredients into the flour mixture and stir gently until just combined. Do not over mix.
Fold in the chocolate chips, if using.
Divide the batter evenly among the muffin cups, filling each about ¾ full.
Bake for 15–20 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Allow the muffins to cool in the pan for 10–15 minutes.
Transfer the muffins to a wire rack to cool completely.
Serve and enjoy!
Notes
When testing for the doneness of the muffins, make sure to not insert the toothpick into a chocolate chip in the muffins. Refrigerate any leftover muffins in an airtight container for up to 5-6 days.