In the bowl of a stand mixer, combine the peanut butter, pure maple syrup, and vanilla extract.
Grind half the oats (one cup) in a blender or food processor (*see note). Add the ground oats, one cup of old-fashioned rolled oats, baking powder, and salt to the wet ingredients. Mix to combine well. Stir in chocolate chips with a wooden spoon.
Refrigerate the dough for 15 to 30 minutes. (You can skip this step if you’re pressed for time, and just use wet fingers to shape the cookies). Use a 1 1/2 inch cookie scoop (or your hands) to distribute balls of dough on a baking sheet. Press gently to flatten slightly. Bake for 10 to 12 minutes, or until set and just beginning to brown around the edges. Cool on the tray for 5 minutes, then transfer to a wire rack to cool completely.
*You can substitute one cup of store-bought oat flour if you don't want to grind your own.