Preheat oven to 350℉. Lightly mist 12 cups in a muffin tin with cooking spray.
Combine the oats, brown sugar, baking powder and salt in a large bowl. Stir until thoroughly mixed.
In a separate bowl, whisk together the egg white, egg, yogurt, milk and vanilla. Add the wet ingredients to the dry ingredients and stir until blended together. Stir in the blueberries.
Spoon the mixture evenly between the prepared muffin cups. Bake uncovered for 22-25 minutes or until oatmeal is lightly browned and a toothpick inserted in the middle comes out clean.