Preheat your oven to 350°F (175°C) and line a muffin tin with silicone liners or lightly grease with coconut oil.
In a medium mixing bowl, whisk together the non-fat Greek yogurt, egg whites, and vanilla extract until the mixture is smooth and well combined.
Add the rolled oats, vanilla protein powder, ground flaxseed, baking powder, cinnamon, and sea salt to the wet ingredients.
Stir the batter gently with a spatula until just combined, ensuring you do not overmix which can make the muffins tough.
Gently fold in the fresh blueberries so they are evenly distributed throughout the batter.
Distribute the batter evenly into the muffin tin, filling each cup about three-quarters of the way to the top.
Bake for 18 to 22 minutes, or until the muffins are golden on top and a toothpick inserted into the center comes out clean.
Remove from the oven and let the muffins cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.