Prepare a 9″x13″ baking dish with parchment paper.
Note: You’ll want to leave an inch or two of parchment paper over the edge on each end so that you can lift the bars out of the pan later on.
Cream the butter and brown sugar together. Beat in peanut butter, eggs, vanilla, and milk.
Add flour, baking soda, and salt.
Stir in chocolate chips.
Press cookie dough into the prepared baking dish.
Bake for 22-24 minutes. Cookie bars will be soft. Allow bars to cool for 30 minutes.
Combine ganache ingredients and melt on the stovetop over low (med/low) heat OR in the microwave in 15-20 second intervals, stirring in between each interval until melted and smooth.
Spread ganache over cookie bars.
Let cookie bars stand another 30 minutes then chill in the refrigerator for 1 hour. DO NOT skip that part if you want fudgy cookie bars. Lift the cookie bars from the pan using the parchment paper and slice them into 24-48 bars.
Video
Notes
Store cookie bars in an airtight container. Best if eaten within 3 days.