Grind the oats. Using a food processor or high speed blender, blend 1/2 cup of rolled oats until you have a fine powder. You'll use 1 tbsp for one baby serving, and you can store the rest for later.
Stovetop Method
Bring 1/4 cup (4 tbsp) water or milk to a simmer in a small saucepan.
Add 1 tbsp oat power and cook over low heat, stirring, until oatmeal is creamy, about 3-5 minutes. Add more liquid as needed to thin to your desired consistency.
Hot Water/Milk Method
Add 1 tbsp oat powder to a small bowl.
Add 2-3 tbsp hot water or milk and stir until smooth, adding more liquid as needed to thin to your desired consistency.
This recipe will make 1 small baby serving. Increase the amount as your baby's belly can hold more food!
If you're in Stage 1, make sure the oats are very finely ground and use more water or milk. For Stage 2, the oats can be ground a little more coarsely and you can make it thicker with less water or milk.
Once your baby progresses from thin purees, you can make quick oats or regular rolled oats.
Some people don't feel comfortable with using cow's milk for babies. I am fine with using it for cooking foods like oatmeal for babies. (Read more on that here.)
Add flavor and nutrients with fruit purees, mashed banana, smooth nuts butters, and/or spices. Just leave out any added sugar or choking hazards!