Preheat oven to 350°F (175°C) and grease a 10-ounce oven-safe ramekin with non-stick spray.
Place rolled oats into a high-speed blender and pulse until a fine flour consistency is achieved.
Add protein powder, baking powder, salt, almond milk, applesauce, and almond extract to the blender.
Blend on medium speed for 15-20 seconds until a smooth batter forms.
Gently fold half of the fresh blueberries into the batter using a spatula.
Pour the batter into the prepared ramekin.
Top the batter with the remaining blueberries and sliced almonds.
Bake for 22 to 25 minutes, or until the top is golden brown and a toothpick inserted into the center comes out clean.
Remove from oven and allow to rest for 5 minutes before consuming.