Spray slow cooker with non-stick cooking spray of your choice.
Mash bananas well to ensure even cooking.
Combine all ingredients in slow cooker and set to the lowest setting (8 - 12 hours), depending upon when you are going to bed and waking in the morning.
Serve with bananas, extra sweetener (like Stevia extract, if desired), cacao nibs, or other fruit of your choosing.
If the oatmeal is too dry, add milk or water to rehydrate to your desired consistency.