Line an 8x8-inch pan with parchment paper, leaving overhang.
In a bowl, mix peanut butter, melted butter, powdered sugar, vanilla, and salt until smooth.
Stir in graham cracker crumbs until thick and pressable.
Press the mixture firmly and evenly into the prepared pan.
Melt chocolate chips with peanut butter or butter in 20–30 second intervals, stirring until smooth.
Spread chocolate evenly over the peanut butter base.
Refrigerate until fully set.
Lift out using parchment and slice into bars.