Cream the peanut butter and the butter in your stand mixer for 30 seconds. Scrape the sides of the bowl to ensure even blending.
Add in the sugar and the brown sugar. Combine until fluffy.
Beat in the egg and the vanilla extract.
First, combine the flour, the baking soda, and the salt together. Then, add them to the sugar and butter mixture. Combine until blended. DO NOT overmix.
Stir in the oats.
Spread the batter into the prepared 13 x 9 pan.
Bake 350* for 18-20 minutes or until a tester inserted near the center comes out NON goopy. The bars will have a light golden color and look like something you'd want to eat.
Set the pan on a wire rack and sprinkle on the chocolate chips. Let the chocolate chips stand for 5 minutes and then spread the chocolate over the surface using a butter knife.
Cool completely on a wire rack.