Preheat the oven to 350 degrees F. Prepare a muffin tin by lining with cupcake liners or spraying with a nonstick cooking spray.
To make the oat flour, measure Quaker Old-Fashioned oats into a food processor. Pulse until you get a fine, flour-like consistency. Measure the oat flour and remaining dry ingredients into a large mixing bowl. Whisk gently to combine, then. set aside.
In a second mixing bowl, combine the wet ingredients. Whisk together to combine.
Carefully add the wet ingredients to the dry ingredients. Fold together to combine, being careful not to overmix the batter. It will appear sticky and scoopable. Transfer the batter into the prepared muffin tin.
Bake at 350 degrees F for 30 minutes or until the tops begin to brown. Insert a toothpick into the center to test doneness. If it comes out clean, the muffins are fully baked.
Transfer the muffins to a cooling rack. Allow to cool slightly, then serve or transfer to storage containers.
Notes
If storing, place in a sealed storage container or bag. Muffins will last up to 5 days in the refrigerator or three months in the freezer. To thaw, set out for several hours or overnight.