Almond flour is available in every grocery store in organic and regular forms. I highly recommend organic blanched fine almond flour for all your baking needs, particularly for making these fantastic cookies.
Almond flour is more expensive than other flours but some markets offer almond flour in bulk bins so you can purchase 1-2 cups at a time as needed. Though I personally find that almond flour prices have gone down some over the years, making this great news for all of us almond flour bakers!