Add ingredients to an Instant Pot or pressure cooker. Stir until combined.
Set Instant Pot to "manual" for 3 minutes.
After the oats are cooked, let the pressure naturally release for 10 minutes.
Release any additional pressure by opening the valve. Stir the oatmeal and wait for it to thicken for ~5 minutes before eating.
Top with a drizzle of peanut butter and banana slices.