Preheat the oven to 350°F and line an 8x8-inch pan with parchment paper; spray with cooking spray.
In a bowl, combine granulated sugar, brown sugar, and eggs; stir well.
In a separate bowl, mix flour, salt, and cocoa powder; add to the sugar and egg mixture.
Fold in the chocolate chips and spread the batter evenly in the prepared pan.
Bake for 20 minutes; a toothpick may come out with moist crumbs.
Let the brownie layer cool completely, which may take about an hour.
Beat cream cheese and peanut butter with a hand mixer until creamy.
Add confectioners sugar and vanilla extract; mix until smooth.
Gently fold in the Cool Whip and spread the mixture over the cooled brownies.
Refrigerate the assembled bars for 2 hours before cutting and serving.