Start by greasing your slow cooker. I rubbed the inside of mine with a couple tablespoons of coconut oil, but you can use cooking spray if you prefer. (Please do not skip this step, people, or you will end up with a literal hot mess on your hands.)
Add all the ingredients to the slow cooker. Give everything a quick stir, cover, and cook on low for 7 hours.
Give the oatmeal a good stir, spoon into bowls and serve warm with toppings of your choice.