Preheat the oven to 350° F.
In a large mixing bowl, combine the oat flour, powdered peanut butter, baking powder, and cinnamon.
Add the maple syrup, then mix again.
Mix in the peanut butter to form a thick sticky dough.
Line a baking sheet with parchment paper.
Roll the cookie dough into 12 balls of equal size.
Place the cookie dough balls on the parchment lined baking sheet, with a bit of space between each dough ball.
Use the back of a spoon to flatten the 12 dough balls.
Use a fork to press the classic criss-cross pattern into the top of each peanut butter cookie.
Bake the cookies for about 10 minutes, until they are golden brown on the bottom.
Let the cookies cool for a bit, then dig in and enjoy!