Preheat the oven to 350 degrees F. Line a 9 x 13 pan with parchment paper or foil and set aside.
Prepare the brownies according to package directions.
Bake according to package directions. Remove and allow to cool.
Meanwhile, prepare the filling.
Pulse or blend in a food processor or blender the graham crackers.
Pour into a bowl and add in the peanut butter, butter (completely melted), powdered sugar, and vanilla extract.
Stir until all ingredients are well incorporated.
Press the mixture evenly over the brownies.
In another bowl add the chocolate chips and peanut butter.
Microwave in bursts of 15 seconds, stirring in between each burst for 10-15 seconds until the mixture is smooth and creamy.
Pour and spread the mixture over the peanut butter layer until it is even.
Allow the bars to sit until firm (place in the fridge covered.)
Once the chocolate is firm, use an extremely sharp knife to cut into squares.