Preheat your oven to 350°F (175°C) and line your baking dish with parchment paper, leaving some overhang for easy removal later.
In a medium bowl, combine the creamy peanut butter, light brown sugar, egg, vanilla extract, and baking soda. Stir until everything is well combined and smooth.
Next, fold in the old fashioned rolled oats and semi-sweet chocolate chips until evenly distributed throughout the batter.
Transfer the mixture into the prepared baking dish and spread it out evenly with your spatula. Bake in the preheated oven for about 20-25 minutes, or until the edges are golden and the center is set.
Once baked, remove the dish from the oven and let it cool in the pan for about 10 minutes. Then, lift the bars out using the parchment paper and let them cool completely on a wire rack before slicing them into squares.
