Put the oats, cinnamon, salt and baking powder in a large bowl. Stir to combine and make a well in the centre.
Add the milk, eggs and maple syrup. Mix the liquid in the well, slowly incorporating the oats until evenly combined.
Add the apples. Mix well.
Pour the mix into a greased non-stick tray measuring approximately 30cm x 23cm (12 inches x 9 inches).
Cover the tray with foil and bake for 30 minutes, then remove the foil and cook for another 15-30 minutes until golden brown on top and set through.
Allow to cool completely, then cut into 16 equal pieces. The squares should lift out of the tin easily.
Enjoy hot or cold.
Your baked and cooled porridge squares should be transferred to a sealed container and placed in the refrigerator within two hours of making.Properly stored in the refrigerator, your porridge squares should keep for 3-5 days.