Preheat the oven to 350°F (175°C) and lightly grease a baking dish.

In a saucepan, bring the water to a boil, then add the steel-cut oats.

Reduce heat and simmer for about 10 minutes until slightly thick but not fully cooked.

Remove oats from heat and let cool slightly.

In a mixing bowl, whisk together almond milk, egg whites, maple syrup, coconut oil, vanilla extract, and protein powder.

Stir in cinnamon, baking powder, and salt.

Add the partially cooked oats to the mixture and mix until well combined.

Gently fold in the blueberries.

Pour the mixture into the prepared baking dish and spread evenly.

Bake uncovered for 35–40 minutes, until the center is set.

Let cool slightly before slicing or scooping.