Lightly grease the crockpot with butter or oil. This prevents sticking and makes cleaning easier. It also helps the oatmeal cook smoothly without burning on the sides.

Pour steel-cut oats into the crockpot. Spread them evenly at the bottom. This ensures even cooking and prevents clumping during the slow cooking process.

Add water and milk into the crockpot. Stir gently to combine with oats. The mixture should look thin now but will thicken as it cooks slowly overnight.

Add brown sugar, cinnamon and salt. Stir well so everything mixes evenly. These ingredients give the oatmeal a warm and slightly sweet flavor.

Add butter and vanilla extract to the mixture. These add richness and aroma. Do not skip them, as they improve both texture and taste.

Cover the crockpot with a lid. Set it on low heat. Let it cook for 6–8 hours. This slow cooking creates a creamy and soft oatmeal texture.

In the morning, open the lid and stir the oatmeal well. It may look thick, but stirring will make it creamy again and evenly mixed.

If the oatmeal is too thick, add a little warm milk. Stir until you get your desired consistency. This step helps make it smooth and soft.

Serve the oatmeal in bowls while warm. Add your favorite toppings like fruits or nuts. Enjoy a comforting and healthy breakfast.