01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners or lightly grease with cooking spray.
02 - In a medium bowl, whisk together flour, protein powder, baking powder, baking soda, and salt until well blended.
03 - In a large bowl, whisk Greek yogurt, eggs, milk, oil, sugar, and vanilla extract until smooth and fully incorporated.
04 - Add dry ingredients to wet mixture. Stir gently with a spatula until just combined—do not overmix.
05 - Toss blueberries with 1 tablespoon flour in a small bowl to prevent sinking. Gently fold into batter.
06 - Divide batter evenly among prepared muffin cups, filling each about 3/4 full.
07 - Bake for 18 to 22 minutes until a toothpick inserted in center comes out clean.
08 - Let muffins cool in pan for 5 minutes, then transfer to wire rack to cool completely.