Prep the slow cooker. Lightly coat the inside of your slow cooker with a bit of butter or neutral oil. This helps prevent sticking and makes cleanup easier.

Add dry ingredients. Pour in the steel-cut oats and rolled oats. Stir in cinnamon and salt so they’re evenly distributed.

Pour in liquids. Add the water and milk. Stir to combine. If using dried fruit like raisins or chopped dates, you can add them now so they plump as the oatmeal cooks.

Sweeten and flavor. Add maple syrup (or honey) and vanilla. Stir again. Taste the liquid—it should be lightly sweet since flavors will mellow as it cooks.

Set and cook. Cover and cook on Low for 6–8 hours, or on High for 2.5–3.5 hours. Every slow cooker runs a little different, so check the first time you make it. The oatmeal is done when it’s creamy and the steel-cut oats are tender but still have a little chew.

Stir and finish. Give it a good stir. If it’s too thick, add a splash of warm milk or water to loosen. If using fresh fruit like diced apples or sliced bananas, fold them in now so they don’t overcook.

Serve with toppings. Spoon into bowls and add nuts, nut butter, yogurt, berries, or extra maple syrup. Build each bowl to match your morning mood.