Line a 9x13 inch baking pan with parchment paper or foil.
In a medium saucepan, melt together the butter and granulated sugar over medium heat. Bring to a boil and cook for 1 minute, stirring constantly.
Remove from heat and stir in the peanut butter and vanilla extract until smooth.
Arrange graham cracker squares in a single layer in the prepared pan.
Pour the peanut butter mixture evenly over the graham crackers.
In a microwave-safe bowl, combine the chocolate chips and butterscotch chips. Microwave in 30-second intervals, stirring between each, until melted and smooth.
Pour the melted chocolate mixture over the peanut butter layer and spread evenly.
Refrigerate for at least 1 hour, or until firm. Cut into squares to serve.