In a food processor, add dates, vanilla and peanut butter and process until smooth. Then add the oat flour, protein powder, and salt and process until the mixture starts to form a dough. If it doesn't seem to come together, add another tablespoon or two of peanut butter and process again.
Form the dough into balls and place on a sheet of parchment paper. Press each ball gently with a fork to make the classic peanut butter cookie criss-cross pattern. Place in the freezer for 5 minutes to set.