01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners or grease lightly.
02 - Whisk together flour, protein powder, baking powder, baking soda, and salt in a medium bowl.
03 - Whisk Greek yogurt, eggs, milk, oil, sugar, and vanilla extract in a large bowl until smooth.
04 - Add dry ingredients to wet mixture and stir gently until just combined. Avoid overmixing.
05 - Toss blueberries with 1 tablespoon flour to prevent sinking, then fold gently into batter.
06 - Divide batter evenly among muffin cups, filling each about 3/4 full.
07 - Bake for 18-22 minutes until a toothpick inserted in the center comes out clean.
08 - Let muffins cool in pan for 5 minutes, then transfer to wire rack to cool completely.