Preheat your oven to 350°F (175°C) and grease a baking pan.
In a large mixing bowl, cream together the butter, granulated sugar, and brown sugar until smooth. Add the peanut butter, eggs, and vanilla extract, mixing until well combined.
Gradually mix in the flour, oats, baking soda, and salt until just combined.
Spread the mixture evenly in the prepared baking pan and bake for 30 minutes or until golden brown.
While the bars cool, prepare the frosting by beating together the softened butter, powdered sugar, cocoa powder, milk, and vanilla extract until smooth.
Once the bars are cool, spread the frosting over the top and cut into squares.
Notes
These bars can be stored in an airtight container for several days. You can also add chocolate chips for extra flavor.
Keyword dessert bars, Lunch Lady recipe, peanut butter bars