Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper if desired.
In a mixing bowl, combine the peanut butter, brown sugar, and granulated sugar. Mix until well blended.
Add the egg and vanilla extract to the peanut butter mixture, and mix until smooth.
In a separate bowl, combine the rolled oats, baking soda, and salt. Stir well to combine.
Gradually add the oat mixture to the peanut butter mixture, stirring until fully combined.
If desired, fold in the chocolate chips until evenly distributed.
Use a spoon to drop tablespoon-sized balls of dough onto the prepared baking sheet, spacing them a couple of inches apart.
Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden.
Remove from the oven and let the cookies cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.