Preheat the oven to 350°F (175°C) and lightly grease a small oven-safe baking dish with a light coating of oil.
In a medium mixing bowl, whisk together the rolled oats, vanilla protein powder, baking powder, ground cinnamon, and sea salt until well incorporated.
Add the nonfat Greek yogurt, egg whites, almond milk, and vanilla extract to the dry ingredients, stirring until the batter is well combined.
Gently fold the fresh blueberries into the batter, saving a small handful to sprinkle on top for a beautiful presentation.
Transfer the mixture into the prepared baking dish, smoothing the top with a spatula and adding the remaining berries.
Bake for 25 to 30 minutes, or until the top is firm to the touch and the edges are a light golden brown.
Remove from the oven and let the oatmeal sit for at least 5 minutes to set before enjoying it warm.