Grease a 9 x 13 inch pan with non stick cooking spray.
Cream brown sugar and butter in the bowl of an electric mixer.
Add eggs and vanilla and beat until combined.
Add baking powder, salt, and flour and mix it all together.
Mix in your chocolate chips then slowly mix in 12 crushed Nutter Butter Cookies.
Press into prepared pan (dough is sticky, spray your hands with cooking spray to avoid it sticking to your hands).
Sprinkle the 4 crushed nutter butters over the top.
Bake at 350℉ for about 30 minutes. Be careful not to overcook - the middle might be a little gooey.
Cool completely before slicing into squares.
Notes
Nutter butters are the best cookies for this recipe for the peanut butter flavor. You could also use store brand peanut butter cookies. Golden Oreos also work great in these Nutter Butter Cookie Bars.