1. Preheat oven to 350 degrees.
2. Spray muffin pan with cooking spray and lightly dust with one tablespoon of flour.
3. In a medium bowl, mash bananas until smooth and consistent, absent of clumps. Next, add egg, yogurt, milk and vanilla extract. Continue to mix until well combined.
4. In another bowl, combine the protein powder, flour, baking soda and salt. Next, fold the dry ingredients into the wet ingredients and mix just enough to combine. Finally, add in the blueberries and gently fold until they are fully combined.
5. Evenly distribute the mix into the muffin pan and bake for 15-20 minutes or until fully cooked.