Starting on low, turn the blender on to start to grind the oats. Move the blender up to high to grind the oats into a flour-like consistency. It may take 15-30 seconds depending on your blender.
Use or store in a mason jar or other airtight container.
Notes
Store for 1 month in an airtight container at room temperature or up to 1 year in a zip top freezer bag in the freezer.
You can use a food processor, though it will not grind into as fine of a texture.
Use as instant oatmeal for babies or toddlers by mixing with a 2:1 ratio of hot water to oats. Add cinnamon or fruit as desired.