Line a large cookie sheet with parchment paper. Set aside.
In a large bowl, combine peanut butter and syrup. Mix with a spatula until completely mixed and a smooth paste forms.
Add in oat flour, one tbsp at a time. Stir and completley mix in 1 tbsp before adding the next. You may need less than the amount stated (explained more in the notes) so do not add the whole amount at once. Add in enough until the mixture becomes thick and looks like a cookie dough that you can roll and shape.
Scoop 1 tbsp of dough and form into ball. Place onto prepared cookie sheet and using the palm of your hand, flatten ball into a round cookie shape about 1/4 inch thick. Repeat with remaining dough. Use a large fork to make criss cross indent pattern on surface of cookies.
Refrigerate cookies for about 1 hour or until cookies are firm. You should be able to peel the cookies off of the parchment paper. Store uneaten cookies in the fridge.
Notes
Instead of oat flour, you can also use coconut flour or superfine almond flour. If using coconut flour you will only need half the amount (about 4 tbsp). If using superfine almond flour, it is a direct substitution for oat flour. Please see the post where I discuss the different results using each of these flour substitutes.
The amount of flour you need to add may vary. Different peanut butter brands can produce different consistency of peanut butter and some are runnier than others. Also, brands can vary in the consistency of oat flour. This is why I recommend you add the flour in one tbsp at a time as you may need less.
If you don't have oat flour you can make your own with rolled oats. Pulse them in a food processor or high powered blender until they become the consistency of flour.
I made this recipe using natural peanut butter. It will work with regular peanut butter but it is much harder to stir and the amount of flour added may be different.
The cookies are sweet but not super sweet as these are meant to be a snack rather than dessert. If you want to add more sweetness you can add 1 more tbsp of maple syrup (stir it in at the end after tasting the dough), but you don't want to add too much more than that because adding too much syrup will make the dough too soft. You can also add some chocolate chips to the cookies for additional sweetness.
The cookies should be stored in the fridge. If left out too long the dough will become soft.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.