Measure the oats you want to use
Use rolled oats or quick oats for best results
Avoid steel-cut oats unless your blender is very powerful
Place the oats in a blender, food processor, or spice grinder
Blend until the oats become a fine powder
Stop and scrape down the sides if needed
Blend again until the texture is even
Sift the flour if you want a finer result
Reblend any coarse bits left in the sieve
Store the oat flour in an airtight container
Keep it in a cool, dry place
Refrigerate or freeze for longer storage