Add the water or non-dairy milk to your Instant Pot. Next sprinkle in the apples, brown sugar, cinnamon, cinnamon sticks and steel cut oats. Don't stir together. Place the lid on the Instant Pot and lock into place. Set the steam release valve to "sealing".
Press the manual button and set to high pressure for 4 minutes. It will take about 10 minutes for the Instant Pot to reach pressure.
Once the 4 minutes are up, allow the Instant Pot to release pressure naturally. This will take another 10-12 minutes. The oats are ready when the float valve drops down. Carefully remove the lid and stir the oatmeal.
Remove the cinnamon sticks before serving. Top with additional cinnamon and diced apple. Add a splash of milk if you like a looser oatmeal.
This apple slicer makes preparing diced apples so much easier.
I do not recommend using dairy milk in this recipe, as it may scald in the Instant Pot. If you don't have non-dairy milk (soy milk, almond, oat) you can use water.
Store in individual meal prep containers (these are the kind that I use) in the fridge for an easy grab and go breakfast. You may need to add an extra splash of milk to loosen the oats up prior to reheating.