Preheat the oven to 350 degrees F. Lightly grease cookie sheets or line with parchment paper
In a medium bowl, cream together the butter, white sugar, and brown sugar until smooth. Beat in the vanilla extract and egg. Beat or mix in the peanut butter until well blended
In a separate bowl, stir together the flour, baking soda, salt, and rolled oats. Add into butter mixture and stir until combined. Stir in the chocolate chips
Drop by tablespoonfuls onto prepared baking sheets and slightly flatten cookies. Bake in preheated oven for 10-12 minutes until the edges start to brown. Cool on cookie sheets for 5 minutes then transfer to wire racks to cool completely