In a large mixing bowl, stir together the melted butter, light brown sugar, powdered sugar, salt, and vanilla.
Add in the graham cracker crumbs and 1 cup peanut butter, and stir until well combined.
Line a 9x13 inch baking dish with parchment, and press the peanut butter mixture into the bottom of the dish. Smooth out evenly.
Refrigerate this for 30 minutes.
After 30 minutes, add the milk chocolate chips and 2 tablespoon. peanut butter to a microwave safe bowl. Heat for 30 second increments, stirring well, until chocolate is melted and smooth.
Pour the melted chocolate over the peanut butter mixture and smooth out evenly.
Refrigerate for another hour and a half. Cut into bars