Preheat the oven to 375 degrees F. Grease a 2 quart baking dish (like an 8×8 or 9×9″ pan).
In a large bowl, combine oats, cinnamon, baking powder, and salt. Stir to combine.
Pour in milk, syrup, egg or chia egg, melted butter/oil, and vanilla. Stir to combine.
Fold in 1 cup blueberries with a spatula.
Pour oatmeal mixture into your prepared baking dish.
Sprinkle with remaining ½ cup blueberries.
Bake at 375 degrees for 35-40 minutes, or until the oatmeal has plumped and the top is golden.
Remove from oven and let stand about 5 minutes before scooping or slicing.
