Add all of the ingredients into a 6 quart sized slow cooker. Stir to combine.
Cover slow cooker with lid and cook on high heat for 4 hours, or on low heat for 8 hours. Oats can be cooked overnight. Oats are ready when thickened and tender.
Add toppings if desired.
Topping Suggestions: Pecans, diced fruit, dried fruit, seeds, maple syrup, honey or stevia.
Milk Substitutes: unsweetened cashew, almond, soy, coconut or other dairy.
You can substitute apples for pears.
You can make the oatmeal with 8 cups of water and then top with milk when serving instead.
I don't add sweetener to the oats when cooking because I think it has a nice natural sweetness already. Also, this allows you to add sweetener later as desired. If you do want to add some additional sweetness, try 1/4 cup maple syrup or honey added to the slow cooker during cooking.
Cooked oats last one week refrigerated in a tightly sealed container. You can portion the oats in individual servings and refrigerate or freeze for a meal prep option.