Prep your pan and oven: Preheat the oven to 350°F (175°C). Line a 12-cup muffin pan with liners or grease well.
Mash the bananas: In a large bowl, mash the bananas until mostly smooth.
A few small lumps are fine.
Whisk in wet ingredients: Add eggs, Greek yogurt, maple syrup, vanilla, and melted oil. Whisk until combined and creamy.
Mix dry ingredients: In a separate bowl, stir together flour, protein powder, baking soda, baking powder, salt, and cinnamon.
Combine gently: Add the dry mixture to the wet mixture. Stir with a spatula until just combined.
Do not overmix. The batter will be thick.
Add the chips: Fold in the mini chocolate chips. Save a few for sprinkling on top if you like.
Portion the batter: Divide evenly among the muffin cups.
They should be about 3/4 full. Sprinkle extra chips if using.
Bake: Bake for 16–20 minutes, until the tops are set and a toothpick comes out with a few moist crumbs, not wet batter.
Cool: Let muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely. This helps set the texture.
Enjoy: Serve warm or at room temperature.
They’re great plain or with a swipe of peanut butter.