Preheat your oven to 350°F (175°C). This ensures your oatmeal bakes evenly and turns golden brown.
In a large mixing bowl, combine the rolled oats, coconut flakes, light brown sugar, salt, baking powder, and ground cinnamon. Stir these dry ingredients until well mixed.
In another bowl, whisk together the milk (or almond milk), egg, melted coconut oil, and vanilla extract until thoroughly blended.
Pour the wet mixture into the bowl with the dry ingredients. Gently fold everything together until combined, being careful not to overmix.
Fold in the blueberries, ensuring they are evenly distributed throughout the oatmeal mixture.
Pour the oatmeal mixture into a greased 9x9-inch baking dish. Spread it out evenly with a spatula.
Place the baking dish in the preheated oven and bake for 30-35 minutes, or until the top is golden brown and the center is set.
Once done, remove from the oven and let it cool for a few minutes before slicing into squares. Serve warm, and enjoy!