Preheat oven to 350 degrees F Mix together peanut butter and sugar. Add egg, vanilla and salt and stir until combined. If desired, mix in chocolate chips. Roll 1 TBS portions of dough into balls and place on baking sheet lined with parchment paper. (or use a cookie scoop to scoop the dough onto the baking sheet) Bake for 8-10 minutes or until bottoms are just barely browned. Let the cookies sit on the pan for 10 minutes before removing them to a wire rack to cool. Enjoy!