01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners or lightly grease with cooking spray.
02 - In a large bowl, whisk together the flour, protein powder, baking powder, baking soda, and salt until well blended.
03 - In a separate bowl, whisk together Greek yogurt, eggs, maple syrup (or honey), applesauce, milk, and vanilla extract until smooth and creamy.
04 - Pour the wet ingredients into the dry ingredients. Mix gently with a spatula until just combined—do not overmix or muffins will become dense.
05 - Gently fold in the blueberries. Reserve a few berries to press on top of each muffin before baking if desired.
06 - Divide batter evenly among the 12 muffin cups, filling each about three-quarters full.
07 - Bake for 18 to 20 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
08 - Let muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.